Start with something to react to.
The hardest thing about an empty Live Set is the first sound in it. "Build a drum and bass loop" is enough to get one, and so is a full brief: bright major scale, shimmering plucks, rolling Amen break, warm sub, 174 BPM. Ask for your own material and it finds it: "a one-shot kick from my trap packs," "chop a break." One-shots land in tune, breaks arrive already sliced into a new pattern, and grooves come from your own groove pool.