It depends on what you mean by "fit". Do you mean they sound out of place? Too loud? Too low? Too flat? All of the above? lol.
This comes with practice, you need to learn to get the right balance between the drums and the music - i.e. mixing. Also, try use light compression plugs on your track to try get the elements to fit together nicely rather than being so seperate. If you are using FL Studio, you can try test this by using the Fruity Limiter on the master channel... play with the limiter's settings until you get a nice fit between the drums and the music.
If you need any more help just PM me or email me.