This site lets board game designers set up feedback forms and solicit responses from playtesters:

https://meepleloop.com/

5 questions to ask after each playtest:

https://pamwallsgamedesign.substack.com/p/5-questions-to-ask-each-playtest

6 types of playtesting, their pros and cons, and when to use each one (video):

https://www.youtube.com/watch?v=OuN_lu9O9RY

Board game design basics: defining your goals, restrictions, the iterative design process, qualities of good games, taking feedback, and more (video):

https://www.youtube.com/watch?v=AAiCR1XVe68

This website lists various board game playtesting and pitching events across Europe:

https://prototyping.games/

This framework for thinking about the different stages of playtesting also helps you know what kinds of questions you should be asking testers each step of the way (video):

https://www.youtube.com/watch?v=MwxxlG8VGqk

Published board game designers offer their top advice to a new designer in this Reddit board game design forum discussion:

https://www.reddit.com/r/BoardgameDesign/comments/1vezq19/im_sure_this_has_been_asked_a_lot_im_looking_for/

Prototyping and playtesting: building a quick, testable version of your game, gathering feedback that matters, and iterating without losing momentum (video):

https://www.youtube.com/watch?v=gOysPDPiPII

Tips for first-timers bringing their board game prototype to a convention for playtesting—a Reddit board game design forum discussion:

https://www.reddit.com/r/BoardgameDesign/comments/1v88dad/seeking_advice_for_going_to_first_convention_with/

You shouldn’t listen to every playtester suggestion, but how can you know which player ideas are worth considering? Here’s a process to help (video):

https://www.youtube.com/watch?v=uxvKT_yTLaQ

10 tips for making a better print-and-play version of your board game prototype for playtesters and publishers (video):

https://www.youtube.com/watch?v=u_Z3rGnXBQc

What one board game designer wishes they knew when they started making games 12 years ago:

https://boardgamedesigncourse.com/what-i-wish-i-knew-about-board-game-design-12-years-ago/

How many times should you playtest a game before pitching it?

https://pamwallsgamedesign.substack.com/p/how-many-times-should-you-playtest

Advice for playtesting your board game at a convention—a Reddit board game designers forum discussion:

https://www.reddit.com/r/BoardgameDesign/comments/1u7kmdm/having_people_play_test_your_games_at_cons_whats/

An in-depth discussion about all the ins and outs of designing, prototyping, and testing party games (video):

https://www.youtube.com/watch?v=QBxqe2BOi-g

A short thread about what to do when players keep forgetting a rule:

https://bsky.app/profile/nickbentley.bsky.social/post/3ml4gke3wis2z

Board game designers share advice they would give their less-experienced selves—a Bluesky game design discussion:

https://bsky.app/profile/eanderssonsunden.bsky.social/post/3mjzfhu2ld22h

A wide-ranging discussion about various board game design topics, including development and how to make your game less fragile (video):

https://www.youtube.com/watch?v=RnAC-92uzWI

Soft skills that board game designers need: giving and receiving feedback, correcting a playtest experience that has gone off the rails, dealing with publishers, and more (video):

https://www.youtube.com/watch?v=0bGs8WSxZE0

The ins and outs of playtesting: when and where to playtest, how to run a playtest, how to take feedback, and good questions to ask your testers (video):

https://www.youtube.com/watch?v=xxp-VSwWQ-o