Pool objects: Instead of instantiating them again and again, create them once and keep a ‘pool’

When the game starts up, instantiate objects (enemies, bullets etc) and store references to those instantiations. This will avoid the overhead of creating content while the game is playing, will improve framerate and avoid stalls caused by the GC.

Defrag Memory: Assuming you’re using .NET (Most of you will be if you’re using Unity), you can defrag memory as of .NET 4.2. Wait until a game finishes and then run a defrag. It might take a few frames but you can easily hide it while you display “Game Over” or show stats, and you’ll have clean defragged memory for the next run of the game.

Version Control: This will be obvious to the guys with more experience, but use Version Control to store your work. There are plenty of systems out there such as Plastic, Git, Perforce, SVN, Mercurial etc. It doesn’t matter which you’re using as long as you have the ability to store what you’ve done and wind back to a previous revision. If you’re not using Version Control then please do or you’re doing game dev without a safety net!