In the end, game design comes down to discipline. We all need inspiration, but the best designers are those who can focus that inspiration and push their minds beyond the easy answers to find innovation in an already-innovative field.
— Jeffrey D. Allers
Work for 15 min, and write down inspiration but don’t work more right away. Let it stew. Games are born from stew.
— Jeremiah Lee (@Jeremiah042)
Remember only a small percent of your game ideas will be any good. The key is to keep trying to discover which ones those are.
— Tory Niemann (@tkniemann)
When prototyping a new game, you’ll have moments you think “what is this pile of garbage?” My advice: Walk it off and carry on anyway.
— Tory Niemann (@tkniemann)

Mark Major of Whirling Derby (@WhirlingDerby) offers advice for new designers:

“Every skill you have helps in game design, because everything can be the basis of experience for a game. Design is about creating an experience, so before anything else, know what that experience is and be realistic about whether you can deliver that or not. Don’t be afraid to cut material out of a game that doesn’t reinforce that experience.

"Also, spend a lot of time with your games. Make them shine. Playtest them. Making games and getting them out in front of people is exciting, but don’t let that excitement make you settle for second best. If you know you can do better, take the time to make it better.”

http://news.thegamecrafter.com/post/42445138546/mark-major-inducted-into-the-hall-of-fame