Lots of pointers for designing solo modes for board games:

https://virtualplaytesting.com/2020/10/gaming-for-one-designing-solo-modes-with-david-digby/

German board game designers association SAZ makes its model license agreement public:

https://www.spieleautorenzunft.de/files/public/Downloads/Model%20License%20Agreement%20of%20SAZ%20-%20public.pdf

Rob Daviau discusses coming up with a catchy pitch, knowing what the core of your game is, designing legacy games, and more (audio):

https://www.thinklikeagamedesigner.com/podcast/2019/11/14/think-like-a-game-designer-23-rob-daviau

An introduction to the basics of board game design and publishing:

http://www.weirdgiraffegames.com/carla/wordpress/2021/01/11/an-introduction-to-designing-and-publishing/

What are programming games?

https://www.thedarkimp.com/blog/2021/01/14/what-is-a-programming-game/

Self-publishing wargames: tips for making files, laying out graphics, and distributing the game (video)

“Reminder: good, clear rule books are the difference between people playing your game and instantly loving it or getting fed up and shoving it back on a shelf.”

— Ann Jones

Lots of tips for getting past design blocks:

http://www.weirdgiraffegames.com/carla/wordpress/2020/12/21/getting-past-design-blocks-with-fertessa-alyse/

What’s important when coming up with a name for a board game? A BoardGameGeek designers forum discussion:

https://boardgamegeek.com/thread/2576031/how-important-name

What characteristics are shared by games that non-hobbyists consider the “best” games?

https://mrbossdesign.blogspot.com/2021/01/the-best-board-games-of-all-time.html

“Green flags”: signs that a publisher or other professional is good to work with—a Twitter board game designers discussion:

https://twitter.com/Drawnonward/status/1346584140473241602

Staying organized in board game design: taking notes, juggling multiple projects, co-designing, and more:

http://www.weirdgiraffegames.com/carla/wordpress/2020/12/07/organized-game-design-with-annamaria-jackson-phelps/

How to find or make boxes for holding your prototypes—a BoardGameGeek designers forum discussion:

https://boardgamegeek.com/thread/2571927/empty-box-prototype

Tips for scheduling out your time before, during, and after a Kickstarter campaign:

https://boardgamedesigncourse.com/kickstarter-board-game-planning-wrap-up/

“Someone will find the shortcuts and exploits in your game that you didn’t expect. And people will do what it takes to win, even if it isn’t fun.”

— Bez

“Game Design 101: if you’re starting out, don’t worry about processes, techniques or publishing. Just. Design. Games.”

— Alan E Paull

Designing games for the mass market (audio)

https://www.boardgamedesignlab.com/how-to-design-games-for-the-mass-market-with-leslie-scott-and-freddie-scott-vollrath

What do “interrupts” bring to turn-based games? A BoardGameGeek designers forum discussion:

https://boardgamegeek.com/thread/2569993/what-do-interrupts-bring-turn-based-games

Best practices for pitching your game to publishers—a Twitter board game designers discussion:

https://twitter.com/TheJayBell/status/1344370475703660547

The “acquire, build, score” framework for looking at game designs:

https://doriadar.medium.com/abs-the-formula-for-building-games-about-building-9f4fb8ce6396