My 3 tips are:
1) Make a small game:
If you make something small you will finish it, and you'll have time to polish it. It's better to make a short and fun game than a big one but not finished.
2) Take breaks:
Sometimes you'll be struggling with an error, if you can't find the solution you'll be amazed by how much taking a break helps.
3) Have fun:
A simple but very important tip.