Synths and Leads
Drum Fills and Drum Rolls
Hi Hats (Open)
Hi Hats (Closed)
Hi Hats (Pedals)
Rides & Ghost Notes
Clicks and Miscellaneous Percussive Noises
Bells and Chimes
Bongos and Hand Drums
Glichy Drums and Percussion
Glitchy One Shots
Glitchy Loops, Repetitive Glitchy Sounds
One Shot Sounds and Transitional FX
Risers, Uplifters, Downlifters
Instrumental Parts and Orchestral Instruments
Pads and Atmospherics
...And so on, you get the idea. This is simply my way of working, you can be as detailed as you like. The point is to give yourself a palette of sounds to work with at the click of a button. You can pencil in some MIDI information, chuck a sampler bank on your track then scroll through that bank by MIDI mapping the sample select to a fader or rotary dial on your controller. That way you have immediate access to 128 instances of the type of sound that you are looking for, It cuts down on searching and also allows you to find sounds that fit your idea better with less processing necessary to do so. I should stress that you don’t necessarily need to use Ableton's sampler feature. I know that many Drum and Bass producers use Native Instrument's sampler, Kontakt, which has the added bonus that lots of sample collections you can buy (though not all) will come with pre programmed sampler banks for this program.
Just bear in mind, if you use Kontakt or another program that sample collections will include pre programmed banks for, that you don't want to sort by anything other than sample type. This might mean you need to adjust the way in which they are saved. It was actually the Canadian producer iLL Gates that introduced me to this concept, and I thought he illustrated the why behind this concept well by likening it to someone working in a trade, building a house. If they wanted a specific tool for a job, say a drill, then they wouldn't go to the Makita section looking for a drill... they would go to where the drills are kept, regardless of brand.
Actually, it might be worth watching this video (below) where iLL Gates explains the concept further and talks about the specifics of programming banks in Ableton. The banks that are shown in this video can also be downloaded here.