Common best practices: These are the ones you apply on all your projects, no matter how big or small. Not applying them usually won't give a performance hit to your game but can still slow down your project's development.

Technical best practices: These are the ones that give a performance boost to your games. These are usually used on big games that require heavy resources or mobile games where there might be technical constraints. Though these kinds of best practices can also be applied to smaller projects, there's little point in optimizing a game that doesn't need to be optimized. Nevertheless, it's still a good practice.