Coordination practice
Every boxer should be familiar with the most common boxing basics, parallel and diagonal footwork.
Parallel hand and foot strike (same hand and same leg) is the most common position when starting your lead hand combination.
Diagonal hand and foot strike (right hand left foot step) is not as common and therefore more unexpected for the opponent.
Practice both positions forwards and backwards, using all punches. Both positions should run fluidly so that when it comes to the fight, you don't have to think how to switch between them.