Shrink/Flatten

Very simple but frequently very useful, the Shrink/Flatten tool scales the selected vertices, edges, or faces depending on their normal. (A “normal” is what the orientation vector of a face is called in 3D.)

To use the Shrink/Flatten tool:

1. Select the parts of the mesh you want to modify.

2. Press Alt + S (similar to scaling).

3. Drag your mouse to adjust the Shrinking value.

4. Left click to confirm the operation.

This tool also has some very simple options. It allows you to adjust the shrinking or flattening value and has some Proportional Editing options as well.