Before sitting down to write your beats, talk with the other musicians about the tune. Pay close attention to the person who wrote the music. Ask questions such as, "What kind of feeling do you want this to evoke?" Or, "Is this song a possible single?" Don't be afraid to get the opinion of the other musicians' opinion on what beat would work in the song. Remember, a group or ensemble is a collaborative effort.
Sit down with the music and listen with opinions, keep an open mind. Make notes about the music. How does it make you feel? What does the music need? What does the music not need? Pay special attention to the vocals and where they come in and to the bass parts, as the bass and drums should be locked in together.
Now sit down at the drums and begin to experiment with beats. Start simple and build from there. If you add more to the beats and it doesn't sound better, then stick with the simple beat.
Be sure to write down any ideas that you think will work with the song for later rehearsals. Be organized with your notes so when you come back to rehearsal you will be able to know where you are at all times.
Rehearse your ideas with the band and listen to the comments of the other musicians. Remember that most people who listen to music are not drummers and are not interested in how flashy you are on the drum set. People respond to music and this requires playing for the song, and not yourself.