Maybe some of you already know, but if not check out the MIDI effects racks (and presets) in the Ableton browser. Just load a track with midi info, and drag the rack or effect into the effect pane, and start tweaking.
For me, presets and racks is a good starting point, but I always go in and start tweaking them so that the outcome is not a vanilla usage of the rack or preset. But it’s a good way to get started.
Note that Ableton is one of the few DAWs where you could actually easily drag in plugins that modify MIDI information, arpeggiators, chord builders and much more. It’s kind of doable in Logic, but you need to learn the Environment world, and I wish it was a quick-start, but that will take a while to get a grasp of. While in Ableton Live, it’s a matter of drag and drop MIDI effects.
Another nice thing with these effects is that you could take older MIDI material that you saved, and reuse it, and most likely with the effects, the output is totally new. Which means that it’s good to save MIDI files from existing productions (note to myself).