Group drills with two or more people on a court can allow you to improve your control and consistency when playing shots. Practicing with friends can be fun and if you want to make it a competitive you can set simple rules along the way with most drills.
Conditioned games are a great way to practice specific shots or game plans while playing points. Conditioned games a informal ways to break down the game but focusing on one aspect while playing and if you are unable to perform you loose a point. So a little more competitive and more similar to match play, which give players more realistic practice for match play improvement.