Hello Jonny i would be glad to help you, but still i just did a babysteps in drawing. I checked your SB and you are doing pretty much the same things I was doing last summer. I would say that two things which helped me most are:
1.Perspective - little bit more understanding that everything has its volume and the craft drawing 3d shapes on 2d surface. These helped me big big time:
http://www.marshallart.com/other/shop/videos/index.php
2.Life drawing classes - because photos are already flattened out and in many of them there is really hard to find some volume. Also photographers like to use front lightning, which is much harder to capture in drawing. As Loomis said "We love shadows :)". I also learned about measuring with angles in life drawing classes which helped me big time with proportions. At first its slow and tidious process but I think it is very important essential. You get faster in time also, so dont worry.
Maybe let me desribe you my process now:
1. I find interesting reference, with good pose ( could be kontrapost or even dynamic pose, but i would start with standing figures)
2. i draw head, chest and pelvis (in this fase only as an egg shapes) and estimate overal height and width of figure. Mosty I use head as a meassuring unit. The go with center line (spine) and check symetry.
3. The i draw limbs and check propotions and realtions with horizontals and verticals (loomis has also page about this). After that i have solid outline of a figure and basic perspective thanks to checst and pelvis orientations.
4. then i flesh out. (now im studing muscles to be able to do that well)
5. then shading where im very bad for now. but i try to do shadow mapping:
https://www.youtube.com/watch?v=fWErCqnYC0Q
6. youre done :)
Also i learned thing or two about proper mindset. Now im trying to be the most precise I can and dont rush anywhere. More work doesnt mean better quality and art is a quality discipline :) Also if you rush from one badly drawn thing to another you carry on you mistakes, so not improving that much.
Hope it helps a little. Sorry for repsponding that late, my internet is not working today (im on phone). Anyways come back later I did some anatomy studies you might be interested in. Ill upload them as i have proper connection.
Be well.
Tomas
Some more Hamptons stuff.