Blender School continued - Some more lessons

 Today's lessons taught me a bunch of stuff.

Booleans!

Bool Tool menu:

Ctrl+Shift+B

Suddenly, I realised that the default mode for Bool Tool is "Brush", which leaves the cutter in play. Lots of times, I want the operator to be immediately applied... So it's Shift plus the Brush keyboard shortcut. Easy!

Boolean Topology

1. All Boolean operations need two connecting edges. Take note that if these connecting edges are not perpendicular to the Boolean's edge, it will cause problems if you try to add a bevel later.

2. No-manifold geometry

Boolean operations may produce unexpected results if applied to non-manifold geometry. That's a mesh that contains gaps or places where parts of the geometry intersect with itself.

3. Use "Exact" mode for Booleans. If your cutter and target have faces that occupy the same place, you might get Z-fighting, where Blender doesn't know which face to render, giving you a weird "both faces render at the same time" issue.

4. Booleans can create Ngons, which break the flow of your mesh topology -- bad topology! Keep an eye out and deal with it if it becomes a problem for your model.

5. You can apply Booleans to your cutter.