I learned these at the poker table:
1. Pay attention - Most of the mistakes that happen at the poker table happen for a very simple set of reasons. You got bored. You got distracted. Important information is flying around you but you are too busy checking out the cocktail waitress.
Distraction is a big issue in the arts as well. It's so easy to get buried in the small things. Why sweat the future of the field? Much easier to keep track of office gossip, or who is having more/less success than you.
This is dangerous. Pay attention to what is happening in the world. Be curious. Not just about the "arts" but technology, pop culture, current trends and anything else that may impact your world.
2. Know your limits - The easiest guy to crush at the poker table is the pretender. He acts like he can afford to lose when he can't. He thinks he has more skill then previous history has demonstrated. He's not in the game to succeed, he is in the game to LOOK successful. Big difference.
Being humble is important. It's important to acknowledge what you do and don't know. It's also important to acknowledge when you are in over your head. That doesn't mean you withdraw from the situation. Sometimes being in over your head is the only way to grow. But if you don't acknowledge that you may not do the work necessary to get the skills/strategy you need to be compete.
If you get those two things right life as a gambler (and all real artists are gamblers) will be much easier.