This Mastering.com walkthrough from the Logic Pro 11 course shows how to build a drum groove by hand, one hit at a time, instead of relying on a preset pattern.
The instructor clicks in a kick drum first, lengthening its note and dialing in a specific velocity, then layers percussion and a shaker on top, softening some hits and accenting others.
A crash gets added to punctuate the pattern before moving on to the bass line.
The real takeaway is about feel: varying note length and velocity hit by hit is what turns a mechanical MIDI grid into something that grooves like a real player.