When I practice posing, I try to visualize the muscle(s) I'm trying to display - its a very mind-muscle connection. Equivalently, most of the poses (except lat spread) are very similar to exercises - so when I'm doing a particular exercise, I try to again visualize what I'm trying to activate, both in the exercise & in the pose. An example is, say a side chest, which is similar to a 1 arm seated cable row. Sure, its a back exercise, but if you're executing it correctly, you would be turning your wrist from neutral to palm up, similar to a side chest, pulling your elbow in close to your side and sticking your chest up & out. Another example is a wide grip lat pulldown as you are executing a rear double bi. For abs/thighs, I do a lot of vacuums for abs. I also like to put a single grip on the lat pulldown and do oblique contractions for ab exercises. Same as doing an abs/thighs variation that displays your obliques.
