For me, when I practice I actually break up the move (if its a flourish). So say I'm doing DM's Syble Helix, I'll practice the opener like 20 times, then move on to the revolution another 20 times, then the packet spin 20 times, then the closer 20 times, then all together 20 times. Once I'm done with that I go over to the mirror and do it 20 times to ensure I'm getting my angles correct. If my fingers still have feeling by then I'll just keep doing and repeating to improve my speed.
For magic, most of the time I just practice two aspects. Firstly, the coordination of my patter with my actions, and secondly, the actual sleights itself. The latter I do in front of a mirror at different heights and different angles so I know where I flash and where I don't. Last practice, find some of your mates and try to impress them. Its kinda rewarding and you get real life practice so to speak. If you flash or screw up well, that's why they're called your mates.