  Interlayer rotation angle couples strongly to the electronic states of
twisted van der Waals layers. However, not every angle is energetically
favorable. Recent experiments on rotation-tunable electronics reveal the
existence of a discrete set of angles at which the rotation-tunable electronics
assume the most stable configurations. Nevertheless, a quantitative map for
locating these intrinsically preferred twist angles in twisted bilayer system
has not been available, posing challenges for the on-demand design of twisted
electronics that are intrinsically stable at desired twist angles. Here we
reveal a simple mapping between intrinsically preferred twist angles and
geometry of the twisted bilayer system, in the form of geometric scaling laws
for a wide range of intrinsically preferred twist angles as a function of only
geometric parameters of the rotating flake on a supporting layer. We reveal
these scaling laws for triangular and hexagonal flakes since they frequently
appear in chemical vapor deposition growth. We also present a general method
for handling arbitrary flake geometry. Such dimensionless scaling laws possess
universality for all kinds of two-dimensional material bilayer systems,
providing abundant opportunities for the on-demand design of intrinsic
"twistronics". For example, the set of increasing magic-sizes that
intrinsically prefers zero-approaching sequence of multiple magic-angles in
bilayer graphene system can be revealed.
