Your game is 3 to 10 times harder than you think it is.
— Elizabeth Hargrave
To make a bridge to the familiar, hobby gamers have to realize what is familiar to a casual gamer.

Worker placement? nope
Variable turn order? nope
Variable set-up? not really
Deck construction? nope
Game phases? nope

You can ask a casual player to learn 2-3 new things at most
— Dominic Crapuchettes
A key facet of modern design is that players are engaged in the game from start to finish. Make losing as engaging as possible.
— T.C. Petty III
Hey you! You know that idea that you have for a new board game? The one you’ve been stewing over for some time now? Well...

GET UP AND GO MAKE IT!

Seriously! Grab some index cards, grab some pennies - whatever you need - and MAKE IT! You’ll thank me later.
— Tim Blank
If you are going to be designing a game, you need to be the biggest champion for that game. If you can’t sit there for three years and talk about this game and talk about how much you love this game and how great this game is, then no one else is going to get excited about that game.
— Tim Blank
Though it might not be required, writing a good rulebook can give you a leg up in not only getting your game published, but getting it published right. If you can’t communicate how your game is played to the publisher, they can’t communicate it to the world.
— Emma Larkins