My advice -- just started doing this myself --

- don't overscope

- don't limit yourself to a platform (language, console/pc/mobile)

- don't be afraid to aggressively cut features

- don't ever think that you really know what will work

- do try things (lots of things)

- do make a great game

- do spend time studying games that sell on your platforms (business development)

- do write terrible code (if you're someone who knows the difference)

- do it fast

- do things that keep your morale up