The best sound you can get with one mic on a drum kit will depend on three things: the quality of the mic, the placement of the mic, and the room you play the drums in. If you're unhappy with the sound you're getting, you can:
1 get your hands on a better mic
2 experiment with placement
3 try a better room
4 get more mics. It's really unusual, and unusually difficult, to get a really good drum sound with one mic. I'd want four minimum - one on the kick, one on the snare, and a couple of overheads - and lotsa people use loads more than that.