The single most important factor is practicing regularly. 20-30 minutes each day is ideal. Though as this is not always possible work out what is an achievable weekly routine for you.
A little bit of practice everyday will see more improvement than practicing for a long time only every now and then.
Here is a suggested routine that you can use for each practice session.
5 steps to full strokes - rebound strokes
Single strokes, groups of 2-8 on each hand.
Stick control exercises
Try playing the rudiments that you know along with a metronome to see how you are improving your speed.
Your teacher will set several exercises or pieces of music for you to work on
during the week.
The aim is to try to master these exercises, by gradually increasing the speed that you can play them each day.
Play Along with Music
Play exercises along with some recorded music.
Practice any songs that your teacher has set.
Play through any exercises or songs from past lessons
This is a good time to play some of your favorite rhythms or songs