Take a look at my [2] link then (Google Scholar or ResearchGate have the PDF without a paywall)! John Edward's group out of Utah made ~30 small exercises exactly like that. "Make a loop the goes to 3", now "Make a loop that goes to 4", now "Make a loop that goes from 2 to 4", ok now "Loop from 4 to 1", etc.
And from my own work and Edwards, students enjoy these types of practices. They seem trivial to us experts, but they are appreciated by novices.