Think small before you punch
A 20 × 25 mm punch only captures a tiny window. Before punching, move the tool over the paper and decide what the miniature version should contain: a letter, logo, color block, icon, face, number or pattern.
Use scraps you can afford to test
If the object matters, test the punch first on spare paper. Different papers behave differently, especially thin receipts, glossy wrappers and folded tickets.
Flatten first
Wrinkles and folds can push the cut off-center. Smooth the material gently before punching. If the paper is very delicate, keep the most important area away from a fold or torn edge.
The best result is not always centered
A tiny crop often looks more interesting when it feels discovered rather than perfectly composed. Let a letter run off the edge. Keep only half a logo. Capture the odd detail that made you notice the piece in the first place.