Every creator should have a mantra. 
I have several, lucky me.
Healthy teams make happy games.
Sustainable development processes and healthy company culture maketh the good game.
Find the fun.
 Find the core of what makes your game special and amplify it to be bold and beautiful.

Iterate often.
There is wisdom in the fourteenth attempt. Seek feedback often.

Elegance in Everything
Keep it neat.

Design for Everyone
Play is for everyone. Be accessible. Be inclusive.

Challenge Everything
Create things that broaden the medium. Burn convention to the ground.

*list is subject to growth when inspired.