Shelby Starnes points out how poor training habits influence development and condition. Amazing how these simple tips are so crucial for the bodybuilder, yet often overlooked.
A muscle won't condition well if it's not adequately developed. Assuming that diet/cardio/supplements are in line, a male that struggles to get his hams and glutes to "come in" is also a male with small and weak hams and glutes.
Weak body parts are often from poor training habits/form. I'll see a guy (or gal) with over-developed traps and under-developed lats. Ask them to perform a rowing exercise and 9 times out of 10 they will row with their traps and midback rather than with their lats. Correcting this can make huge changes in a physique over time.
Source: Shelby Starnes's Facebook