Once you are in Edit Mode, you reshape the form by acting on its components.
Select, then transform
Select a vertex, an edge or a face, then apply exactly the same transformations as in Object Mode: G to move, R to rotate, S to scale.
Two must-have tools
- Extrude (E key): pulls new geometry out of a face. Perfect for stretching a shape.
- Inset face (I key): creates a smaller face inside an existing one.
- Bevel (Ctrl + B): softens a sharp edge by turning it into several edges.
By combining selection and extrusion, you turn a plain cube into a complex object, one step at a time.
Key takeaway: extrusion (E) is the modelling tool par excellence. Select a face, extrude, repeat.