My ratios vary a lot depending on the genre, but my ratio usually ends up at around 4:1 on toms and snare. Snare might get a bit more if I really want it to SMACK, same with metal kick. I'm quite new to compressing overheads so I don't have any tips there, would any of you other guys mention what you do to overheads?
Attack is crucial, I usually end up at between 10 and 30 ms on most aggressive drums, release depends on the decay of the drum and the tempo of the song. At the moment I prefer to have my attack settings a little bit slower than 10ms, maybe around 20-25, but I'm only using ITB compressors. I've noticed that my attack settings also vary a bit with how much I compress the drum, especially on snare. If I use less compression I often use faster attack times, while I've found that reasonably fast(10ms) attack times don't work that well if I'm compressing the shit out of a snare drum.