For filters try looking at filterfreak 1 or 2, auto filter etc... The concept is that the filter has a resonance that moves up and or down and has distortion set to that. You can also set up step filter like with the moog filters.
For interesting rhythms either samples some breaks and cut them up mpc style. not per transient but per 1/4, 1/8th or 16th. Play the rhythm in any order and something will pop out.
You can also clap a rhythm and remember to anyone reading, your melodics and harmony can have different rhythms :)