Oh, and also feel free to post player's bodyshape suggestions and tweaks, as some players bodyshapes are way off in the default 2k roster.I want to make this thread a resource for roster makers to make their roster's as visually accurate as possible, so please contribute with your own tweaks as well.
I don't take any requests.
Credits to clarkmylove for allowing me to use some as a base.
UPDATED: Guide for the Tweak values.

Bodytype values start from 0-7. Below are the groups.
First bodytype group is skinny, ectomorph type. Values are: 0-2
Second bodytype group is the built, mesomorph type. Values are: 3-4
Third bodytype group is the heavy, endomorph type. Values are: 5-7
Note, there are real no differences among the values within the groups, so stick to using the first value. (0, 3, 5).
Now, the bodytweak values (Categories in parenthesis means that they are the same, just with inverted values):


(BTShldrThck & BTShldrThn): Modifies the size of the upper arm (elbow and up). For thck, positive value is to enlarge, negative is to shrink. Vice versa for Thn.
(BTFarmThck & BTFarmThn): Modifies the size of the forearm (elbow and down). For thck, positive value is to enlarge, negative is to shrink. Vice versa for Thn.
??BTSmth??: Modifies the shoulders. Positive value lowers & rounds the shoulders, while a negative value raises the shoulders. Here's an image for reference
BTChstSize: Widens or narrows the shoulders & a bit of the chest. Positive value to widen, negative value to narrow. Note that for this value, extremely end values (127, -128) will yield the same results, that of the shoulders being disproportionately wide. Reference image
(BTLegsThn & BTLegsThck):Modifies the legs from the knee up.
BTClvsThn: Modifies the size of the calves.
And that's it in a nutshell
Joe Johnson
Bodytype:0
Values:
(BTShldrThck:20)//(BTFarmThck:50)//(BTSmth:-10)//(BTChstSize:25)//(BTLegsThck:20)//(BTClvsThn:-15)
Chris Paul
Bodytype: 0
Values:
(BTShldrThck:30)//(BTFarmThck:60)//(BTSmth:35)//(BTChstSize:30)//(BTLegsThck:40)//(BTClvsThn:-10)Dwight Howard
Bodytype: 0
(BTShldrThck:45)//(BTFarmThck:55)//(BTSmth:-30)//(BTChstSize:40)//(BTLegsThck:20)//(BTClvsThn:-5)Lebron James
Bodytype: 0
(BTShldrThck:50)//(BTFarmThck:60)//(BTSmth:5)//(BTChstSize:10)//(BTLegsThck:35)//(BTClvsThn:-25)Yao Ming
Bodytype: 0
(BTShldrThck:5)//(BTFarmThck:5)//(BTSmth:20)//(BTLegsThck:35)//(BTClvsThn:-10)
Kyle Lowry
Bodytype: 3
(BTShldrThck:10)//(BTFarmThck:10)//(BTSmth:30)//(BTLegsThck:40)//(BTClvsThn:-40)Carl Landry
Bodytype: 0
(BTShldrThck:35)//(BTFarmThck:35)//(BTSmth:15)//(BTChstSize:30)//(BTLegsThck:50)//(BTClvsThn:-30)