Tip #0: Choose your development device wisely
The slower, the better. However, don't overdo it.
Having a too slow device will slow you down and will make you optimize too early,
when is not necessary.
I guess somewhere in the middle is where the virtue is.
Optimizing Build Size
Sometimes your games will use far too much space for no reason at all.
Keeping the size of your build is very important as it will affect directly how many people will be able download your game. Also is important to note that when users need to un-install games from their device they will usually start with the bigger first. Call it survival
Tip #1: Compress textures and audio files