No creep spread from main to natural

The only reason you need creep between your natural and main is to move units back and forth more quickly. Drones don't get a speed boost, so with a typical build this is just a single queen as it rallies to your expansion.

It's nice to have, and people usually do it eventually, but early on in the game your Queens are heavily energy-limited and that energy is better spent spreading creep for map control, scouting, and most importantly for defense.

Terran and Protoss armies that don't clear creep before attacking open themselves up for surrounds, and so simply spreading towards your opponent's base is usually sufficient to slow down an attack.