The least expensive and easiest way I can think of to become a better athlete or powerlifter is to pick up an Elitefts mini short band and use these exercises. There are a million uses for these bands. These are just my two personal favorites.
Band Wall Walks: I use these with my athletes as part of our warmup for almost every upper body lift. It doesn't matter if you're a powerlifter or an over head athlete, keeping your shoulders healthy is the best thing you can do for yourself.
As you can see in the video, when you perform band wall walks: Try to keep your hands at least shoulder width apart, take small steps, about half of a hand length at a time, up the wall until your arms are fully extended and walk them back down to your shoulders. I usually have my athletes perform 10 reps *up and down is one) in between the first 3 warmup sets of their upper body lift.
Band Side Steps: These are my go to warmup/ injury prevention movement for our lower body lifts. I see a lot of young athletes and powerlifters alike who have issues with knees caving in during squat, these should be a MUST for those lifter.
As shown in the video (2nd Instagram video): Keep an athletic stance, with your knees bent and butt back ( the lower you sit, the better). On the side steps be sure to only move one foot at a time and not to drag your feet. I have my athletes perform 3 sets of 10 yards down and back (facing the same way) between their warmup sets of squat or deadlift.
Like I said, there are a million uses for these bands, these are just two of my favorites for both lifters and athletes.