This guide is in a draft state and may not be complete.
The main objective of a 0% run, is to complete the game while avoiding expantions such as Missile Tanks, Energy Tanks, and Power Bomb Tanks. However, you can pick up major items such as the Charge Beam or the Varia Suit.
There are many variants of Unrestricted routes, ranging from beginner friendly routes like the Storm Skip Route or more difficult, but faster routes like the Wave Skip Route and by extension, the Raven Beak Skip Route. However, since you can't pick up expantions, this may mean that you have to utilize slower routes in order to avoid picking up an item.