Practice controlled loop-tool cuts
Think of the loop tool as a tiny clay excavator. You need to learn its language before you trim a real piece.
The drill
Take a leather-hard test cylinder (something you don't care about) and make a series of even cuts around the outside with a loop tool.
What to aim for
- Consistent depth on every pass
- Even spacing between cuts
- Clean ribbons of clay curling away (not tearing or crumbling)
If the clay is crumbling
It's too dry. Mist lightly and wait 10 minutes. If it's smearing, it's too wet; let it firm up.
This is a throwaway piece. Be bold. Get a feel for how hard to press.