Two things most pitches to publishers lack: what makes the game unique and how will it become a hit:

https://www.nickbentley.games/bad-board-game-design-pitches/

“Customers will likely play your game more in the first month of its release than all of your playtesting combined.”

— John Brieger

Graphic design tips and what game designers should pay attention to when working with graphic design elements (audio):

http://ludology.libsyn.com/ludology-204-the-eyes-have-it

“There are many reasons to make games — making a commercially successful product is only one measure of success.”

— John Brieger

“When writing game rules, be wary of VAST COSMIC FORCES that occupy the negative space when you don’t identify the actor in a sentence. Example:

”The deck is shuffled.”
BY WHOM?...
BY VAST COSMIC FORCES!

Try “Shuffle your deck.” or “Each player shuffles their deck.””

— Daniel Solis

Tips for designing games with dice:

https://twitter.com/playnyctophobia/status/1155989285658492928

How to meet with publishers at conventions even if they’ve never heard of you:

https://boardgamedesigncourse.com/how-to-meet-with-publishers-at-conventions-even-if-theyve-never-heard-of-you/

Board game designers share their thoughts on the issue of balance:

https://design100.org/26-balance/#

What to make of a playtest that flops after one that goes well?

https://boardgamedesigncourse.com/from-good-to-bad/

The six zones of play: the physical areas that compete for players’ attention during a game:

https://mrbossdesign.blogspot.com/2019/07/the-6-zones-of-play.html

A look at objectives and how they work in games:

http://makethemplay.com/index.php/2019/07/24/in-game-objectives/

Reconsidering what makes a decision meaningful:

http://www.kindfortress.com/2019/07/25/playful-thoughts-meaningful-decisions/

Thoughts on making games easier for players to learn through rules, components and presentation:

https://hollandspiele.com/blogs/hollandazed-thoughts-ideas-and-miscellany/thoughts-on-making-games-easier-to-learn

Game designers discuss whether they think about any messages their game is sending to players:

https://design100.org/25-messages/#

“Write down notable quotes from players. You can refer back to them during postgame discussion.”

— John Brieger

Phil Walker-Harding discusses how to make games that are accessible to a wide range of players, making a living as a board game designer, working with publishers, and more:

https://www.boardgameatlas.com/forum/WbnHpdyNiO/why-phil-walkerharding-created-a-game-about-sushi-a-look-at-sushi-go-imhotep--more

A discussion on the psychology of cheating in board games (audio):

https://boardgamersanonymous.com/engn-episode-146/

“As a game’s inventor, I’m the LEAST qualified to have final approval on its rulebook. Always get multiple eyes on it before going to press, especially if it’s a small rulebook.”

— Daniel Solis

“Pay attention to the whining of your testers. Even if they are objectively wrong, their emotional human response is a prophecy to the emotional human responses of your future customers.”

— Grant Rodiek

“There’s a difference between providing players advice and taking their moves for them / telling them what to do.”

— John Brieger