Work on side projects alongside your main project, this will help you relax[1].
When stuck on a problem, use a pen and paper to write down and try and solve the problem.
Loops are your friends, avoid copy and pasting.
Use a decent IDE that will help speed up development.
Learn binary, useful for all types of programming.
Get others to test your game, what seems intuitive to you might not be intuitive to others.
If you have an idea for a game that's really big and you've just started game development, you first game will be badly developed; this is why it's important to make lots of small projects rather than building a massive project on your mistakes. Only when you're good enough to perfect the starting layout should to start making a large game[2].
Teach other, you might learn from it yourself as you need to make sure everything you know is 100% correct.