One trick I like to use with leg press is keeping my feet close together, as opposed to keeping them far apart. The distance between my feet is usually heel to heel with maybe a little room in between. What this does is it puts more strain on your glutes, firing it up and getting more gains out of the exercise. Remember to always go all the way down, and push with your heels. It doesn't matter if you have a hundred plates on there if you have bad form.