Drums: Bass Drum - dry or some distortion. Toms, hats, and cymbals get some mild to wild reverb depending. I also sometimes heavily gate toms for that "Phil Collins" sound. Ocassionally I'll put a huge reverb with a long decay on a snare for certian uses. Also delays from sweep to ping pong can be alot of fun on snare for a kind of multi hit or roll effect.
Strings: Big reverbs like in a concert hall
Synths: Depends on the synth...usually one of the onboard effects associated with that synth
bass: Finger or picked - Mostly dry...Slapped - Compression
Guitar: Reverb, Delay, Chorus, Modulation, Distortion as the need arises
leads: See above
pads: Reverb
brass: Reverb from hall to room depending on the feel I'm looking for
Vocals: Reverb, chorus, compression and delay
I tend to use mild to severe compression on almost everything but try not to overdo it as you will probably need to compress the entire mix when mastering.
Its also easy to overdo reverb and end up with a really washed out sound. You can fix this somewhat with a gate to cut off the reverb tails.
If you have enough effects processors, record everything you can dry and tweak effects in the mixing process. The effects will sound vastly different when included in the mix. Exceptions to this are guitars as folks who play guitar tend to have thier own effects rigs. Try to talk guitarists into leaving the reverb out if possible because studio reverbs are almost always better than that included in guitar amps and stomp boxes. If you give 'em a bit of reverb in thier headphones that should help.
Use your best processor on the vocals and the lead parts.
Sometimes you have to ignore all the advice and try something different as well
