jehoshabeath

I would suggest you have this measurement taken while in a seated postion and in shorts. I would also suggest you have someone do it for you.Now when seated you will see the natural fold that occurs behind the knee between the back of you calf and thigh.
Take the measurement along the back of your calf. Starting at the bottom of your feet (ball) up to a point that will likely be an inch or two below that fold. Basically what you want is to avoid having what will be the top (shaft rim) of the boot cut into the back of the knee or touching your thigh.
Hope this makes sense.

Best wishes as you work on these.  The black armor of shadow troopers does look really sharp

One of Needa's men said "Sir, Lord Vader demands an update on the pursuit".

i want to make a navy trooper now....

Lastly, cut a thin strip of foam for a mic tip, add a small bead of hot glue, and wrap around boom. Be careful not to burn yourself like I did.

 
I used shoe goo to glue the felt pieces around my headset wire. Let dry and voila! Here is your completed headset! I left the clamp on the end of my wire to have a way to keep it in my jumpsuit pocket, I glued the wire end into the hole at the bottom of earpiece

 
Here are some selfies, better pics to come!

 

 

 
Hope this tutorial helps you to build your own! Good luck and have fun!

My first costume for joining the 501st is my ISB Officer.
I also have my Biker Scout now, which I prefer to wear a lot of the time as, I'm not seen by ex in-laws when trooping out and about ( don't like going to Car Show troops unless I can be hidden)
I'm also working on a non canon outfit that is for any non canon events, and I have most of it, just have to put it all together after some painting and sewing  
And have another that I'm working on in conjunction with a Squadmate. It's just in the planning stage at the moment  

Cool - you look great!  Did you walk the 10km for that event? 
 
Also, happy 10th anniversary

My first 501st costume was a TX trooper in 2009 & my current IOC setup
I chose the TX because I love the Stormtrooper look but wanted something different than the traditional to stand out. I retired it a couple years later. People either thought I was a TIE pilot or a 'mini darth vader'
I also have a Phase 1 Clonetrooper, a ANH Stunt TK & completed the new TFA Stormtrooper

My very first costume in the Legion was Warrant Officer (straight leg version).  I had fully intended in going for a Tusken or a Gunner, and then saw TIE Reserve or Crewman would be easier to get into, so shifted focus to that.  Then I got a flightsuit ... and discovered that standard men's sizes in flightsuits are just not flattering on me.  I didn't know anyone at the time that could assist in creating a custom fit flightsuit, and I already had the jackboots, so reviewed what I could get into with jackboots that didn't require a flightsuit.  
 
Thus, me picking Warrant Officer
 
After that, it took only a few adjustments (and a lucky find with DW Designs) and I have my Navy Trooper.
 
Other builds that I am currently working on are Galactic Marine, B-Wing Pilot, and Tusken Raider (male).  After that, I am done ... unless I come across anything in Ep7 or Rogue One that really calls to me.

And then we have the Junior Enlisted uniforms.

I have a lot of different costumes, but I'll just share my IOC ones. 
My second Legion-approved costume was the Navy Trooper. I always liked that they were the henchmen that are practically in every scene in the OT, yet most ordinary people can't seem to remember them. I also thought it would be fun to do the Star Wars version of what I felt was equivalent to my job (at the time) in the military.
 
 
ESB version

 
Then I thought it'd be fun to do an officer





 
A little non-canon fun

My first one was the Mechanical Crew. MonCal showed me this "unseen" character in a screen cap and I pushed him to make one with me. We and a few others got together and made a few more. As we were finishing up MonCal and I wrote the CRL.
While waiting for the costume approval, we did a fun phot shoot..
Us...

Screencap:

It was such a fun project! The only drawback while trooping is no one knows who or what you are so I wear it while I drive my MSE droid!!

Well my first one is the Staff Officer I finished last month and my first troop in it will be in 2 weeks.  But....I have already ordered a TK kit, and in the process of beginning a Tusken Raider.  All before my first troop in my only completed costume, lol.   By the way....if anyone is looking to start a TK, ANOVOS is having a great deal through May 4th.  Full kit, only missing boots and blaster, for $350.
 
http://www.anovos.com/products/star-wars-classic-trilogy-imperial-stormtrooper-pre-order

Well the first IOC costume that I completed was my crewman, which doubles up as mi TIE pilot - reserve. I picked it as I knew it would be the starting off point for other costumes. Shortly after my IC I got my first Staff Officer which got replaced a few months later with another set. Other costumes that I have are the Navy Trooper (both versions), Warrant Officer and Imperial Gunner.
Im currently working on a TIE Pilot and a AT-AT Driver. I also jumped on the Anovos TK kit bandwagon. I would like to eventually get a Line Officer and AT-AT Commander as well.
To me costumes are like potato chips.... You can't have just one.

I started with a TK.  Then I caught the bug, I did a Bridge Crewman, Line officer, Heavy Weapons Trooper, Navy Trooper, Warrant Officer, Navy Trooper (Dress Uniform),  Staff Officer, Scanner Crewman and an AT-ST Driver.  I even did an X-wing pilot and Jedi. I Currently working on a TFA Stormtrooper, TIE Pilot and AT-AT Commander Armor.
 
Other than that, I haven't done too much...LOL!

First 501st costume was Vader. I literally had it on for submission pictures, got approved and the next week I had my first troop. My feet were screaming (boots weren't broken in), I had no idea how things were supposed to fit (had everything to tight) almost hit a cold air vent, doorway and various other things (not taking into account I am over 7 feet tall with it on) after I put it on in the underground parking. No fans yet, walked around for 2 hours could barely move without people wanting a picture... had a blast!

My profile pic is my first 501st uniform on my first troop, doing staff officer at Stocktoncon. I had a crappy costume base hat with a greeblie added and a garment leather holster I finished that morning before the con, both since replaced. I always loved the staff officer on ANH and the cool blaster so that's where I started in IOC, but I love my ANH Dress Naval Trooper the best. The helmet is just "me". I have a lot of love for my line officer and is probably my best uniform, but you have to carry yourself differently and be 'in charge', and those jodhpurs are tight!

My first one I completed was my scanning crew and my first troop was a Toys for Tots event in colorado springs and it was fun. I'm currently working on a stormtrooper, reserve tie piolt and a 181st Tie piolt.

My first costume was the Warrant Officer.
 
I went the IOC route for my first build because I thought it would be the quickest and easiest way to get apprvoed in time to march it in Star Wars Weekend for my honeymoon (which I did do in my Gunner - check out this video, they give a big shout out to me and my wife!!!
). 
The warrant officer was my first one because I was debating going with CosplaySky and another memeber told me he had an extra tunic that was too small for him. I tried it on, it mostly fit me, had to get it tailored a little but I went with it. So I just bought some black trousers and was approved!
 
I have a lot of other builds (Crewman, TIE, Staff & ISB Officers, Gunner) and have more on the way (Line Officer, TK, Bith, Wedge Antilles, and Thrawn). But the Warrant Officer will never be my favorite one. My go to costume is my Gunner. I love it. I love the mobility, I love the comfort. It's not the most recognized costume (my TIE is right now, but those hoses and chest box suck!). But being able to kneeldown and pick up a kid for a great picture is always so rewarding.

BTW... 
1.  I would use the more measurements the better approach but be sure to include that in your response along w/ what ever diagram you used.
2.  I trooped day in and out through celebration walking all over the place with no inserts and these boots ROCKED.  Anyone who saw me there those were the boots and they are outstanding.

When measuring make sure you wear your pants.  Most fabric won't be super thick, but you had a pair of tall socks and the pant fabric it can factor in with the measurement.  

I found the answer!
In Issue 40 of the Star Wars Insider magazine, there's an article about Motti on pages 18-20. The article quotes Mr. LeParmentier, "they had this white uniform picked out, but it was for a guy about 5'5", and it obviously wasn't going to fit. So I was outfitted like the rest and became General Motti."
I wonder if the white uniformed officers were originally intended to be Navy officers.

Megan,
 
Was looking through some folders and found a copy of the image. Of course I would still double check with Francois.
 

I found the answer!
In Issue 40 of the Star Wars Insider magazine, there's an article about Motti on pages 18-20. The article quotes Mr. LeParmentier, "they had this white uniform picked out, but it was for a guy about 5'5", and it obviously wasn't going to fit. So I was outfitted like the rest and became General Motti."
I wonder if the white uniformed officers were originally intended to be Navy officers.

Very Jealous!  Wish I could've been there.  But I did get approved while everyone was away, so I'll see you next time!  Which by the way....  Did they announce where and when the next one is?