Well, I'm a drummer, so writing rhythms is something I usually spend no time on what so ever, granted I have a few tips that might help you out here.
- Tabs. If there's a song you really like the beat to, don't be afraid to look up the tabs and emulate them. The entire dance music scene has been perpetuating the same rhythms for decades now. Who cares if you look up a tab and copy the beat. I'll tell you who: no one. If they do care, they're fucking stupid. Worry more about getting a good drum kit together. It's harder to get a good kit than a good rhythm.
-Effects! Try throwing some reverb on the hats if you need them to take up a little extra space. Some distortion can help make those hats a little more potent. A really good way to to write rhythms with out actually writing them is to get two or three hi hats. Have one hi hat with delay on it and accent whatever you feel like with the second hat. Instant dynamics! woooo!
- A kick on the one, a snare on the two and four and a hi hat for every number 1-4. There's the skeleton to a good rhythm. Now fill in the blanks :3
- Rests make for excellent dynamic situations. Try to have just a kick fill the space on the one, then have all the instruments come in on two. Or have the drums rest at the beginning/ end of a measure. Experiment with them. I find that a reverse cymbal leading up to a rest helps accent the silence, as will a normal crash when the groove returns.
-16th notes. Hi hats. Not everywhere, but in some places. you can be kind of random with them. No one will notice/care.
- If you're interested in more experimental breaks, listen to other artists and just try to emulate them. There's nothing out there that hasn't already been done rhythmically, so just try not to think of originality. Again, find tabs.