Most likely all users know how to load the Platonic solids into Stella, but do you know the fastest way?
It can be done very quickly just via the keyboard.
First use Ctrl+N (same as File->Polyhedron List, the N stands for New, as in loading a new model).
Then enter the first letter of one of the five Platonic solids (T, O, C, I or D). This is enough for Stella to know what you're referring to, and you will see the appropriate polyhedron highlighted in the list below.
Then just hit Enter and your model of choice will appear.
In practice it's very quick:
Tetrahedron: Ctrl+N, t, Enter.
Cube: Ctrl+N, c, Enter.
Octahedron: Ctrl+N, o, Enter.
Dodecahedron: Ctrl+N, d, Enter.
Icosahedron: Ctrl+N, i, Enter.
Loading many other common polyhedra can be similarly quick, eg:
Truncated Tetrahedron: Ctrl+N, tt, Enter.
Cuboctahedron: Ctrl+N, co, Enter.
Small Stellated Dodecahedron: Ctrl+N, ssd, Enter.
Johnson Solid J1 (square pyramid): Ctrl+N, j1, Enter.
Rob.