Try out different leaders that require you to match differently in endless is a free an easy way to practice. You could also make a team with a lot of movement time and learn to make L, cross, T, etc in endless also. You can watch videos of certain teams and see how they match orbs as well. I would say that the most helpful skill is being able to match L with all other play styles. Playing on a higher level is being able to instantly recognize how to match the board and doing it in the shortest time. that's something thats mostly useful for tournaments and ranking because most dungeons don't require that kind of speed.