I believe, just like this title and common saying suggests, practice makes progress. I'm convinced that if someone is practicing consistently, it boosts their confidence, their skills improve and as a result, their piano playing improves. This will also help ensure a more successful piano lesson. Here are a few little practice tips that may help with your practice time:
Consistent practice is key; practice a little bit everyday.
Go over your practice notes from the teacher and make sure you're practicing what was assigned.
If you're making mistakes, go back and fix them before you move on.
Make practice time a part of your daily routine.
In addition, make sure your piano or keyboard is in an easily accessible place. I think we are much more apt to practice if our keyboards/pianos are set up in a place that is easy to get to.
Here are some practice ideas, daily, practice the more difficult parts, practice what was assigned, make sure your piano/keyboard is in an accessible place, not in the garage, too hot or too cold, make sure it's comfortable, etc.