by parallel process do you mean like glue compression? or layering up effects, it's sort of a grey area in my book so I guess I probably don't do it right, and what sort of processing on my drum bus? (by bus do you mean group? i.e where it effects a bunch of tracks, sorry ableton user here >.>) yeh I usually sidechain my kick and snare to the rest.
I'll try and explain what i do the best i can. I don't know how it is done in Ableton but I'm sure you have the same options as you do in logic.
When i import my drum samples i'll make my kick and snare channels mono instead of stereo (any layered snares will remain stereo). Then I'll send each one of those channels to a bus (yeah a group pretty much, it took me a while to get my head around it too). I don't know how to do it in Ableton but in logic you have the option to make the send (to the bus) pre fader which basically means if you lower the volume on the original kick and snare track the full signal will still be sent to the bus (maybe google how to do that one in Ableton).
When I have the kick and snare sent to an individual bus I will quite heavily compress each one. It's up to you how much. EQ also and add effects to get the desired sound.
When you're happy with it drop the fader on the bus all the way to the bottom and while playing the drums only increase the fader on the parallel channels until you have enough of the signal coming through. Hopefully that makes sense. If not pm me.
Drum Buses
Some people do this kind of thing at the end on the mix down but i do it all from the start. Audio does it this way too so it works for me haha.
When I create a drum track I will send every individual drum/percussion part to a drum bus (group) but i will not make this send pre fader (like i do with the individual kick and snare) i make sure the audio is sent to the bus 'post fader'. I will do the same with the synth tracks, bass and FX/Vocals etc. So on my mixer i will have all the individual sounds send to their relevant bus and add a bit of compression (like you said just to 'glue' all the sounds together a bit).
I've only been at it for 14 months so I'm still learning loads every track i do but this works for me for now. I suggest (if you haven't already) that you watch Subfocus's tutorials because they are really helpful! Just pm me if you have any other questions.
I forgot to say also when compressing drum make sure the compressors 'Knee' setting is set to 0. You don't want a knee active when compressing drums.