Half a dozen board game designers discuss all the various steps of making a game (video):

https://www.youtube.com/watch?v=qG3oX9H8RAo

Where and how do you playtest your games? A Twitter board game designers discussion:

https://twitter.com/ajstichter/status/1642616698187444227

A simple method for sorting through playtester feedback:

https://twitter.com/dr_vil/status/1638893021965205504

Tips for preparing to show your game design at a public playtesting event:

https://www.fightinabox.com/single-post/prepping-for-protospiel

Tips for setting up a playtest night where designers may come with games of different lengths—a Twitter board game designers discussion:

https://twitter.com/PhilSchwarzmann/status/1619083003027951616

Cardboard Edison’s annual Best Practices book filled with original articles and interviews about board game design that you won’t find anywhere else is out now:

https://drive.google.com/file/d/1oHHAAgAcRS9gH4YUMQ5kL310lv0NrOwQ/view

See also: https://cardboardedison.com/award

Where to find playtesters to try out your board game design:

https://boardgamedesigncourse.com/where-art-thou-playtesters/

A broad overview of how to make a board game, from idea to prototyping and playtesting, to getting it published (video):

https://www.youtube.com/watch?v=y9OCSwxEd9E

A handful of quick tips for running an effective playtest session (video):

https://www.youtube.com/watch?v=strkQM8P9F4

A huge roundup of tips for becoming a better board game designer (video):

https://www.youtube.com/watch?v=EQ4XZpBD8Sc

Playtesting conventions: what new board game designers need to know about attending (video):

https://www.youtube.com/watch?v=vdojDP4Ywpg

Receiving critical feedback—from playtesters, reviewers, or publishers—is tough. Here are some tips for how to handle criticism well (audio):

https://www.wintermoongames.com/podcast/episode/d2d40db7/how-to-take-criticism

Designers share their biggest secrets for designing and playtesting board games:

https://twitter.com/BreakMyGameG/status/1572066930667950080

Specific questions to ask playtesters (and other things to look for during a test):

https://boardgamedesigncourse.com/playtesting-questions-to-ask/

What's your preferred way to take notes or record information for a playtest? A Twitter board game designers discussion:

https://twitter.com/BreakMyGameG/status/1570863761409585152

What are your favorite questions to ask playtesters about your designs? A Twitter board game design discussion:

https://twitter.com/BreakMyGameG/status/1567541343714512897

Playtesting 101: everything you need to know to get started with testing out your board game design (video):

https://www.youtube.com/watch?v=WKd4WJi5VBI

Why you need to playtest your game both with other designers and with non-designers:

https://twitter.com/StoicHamster/status/1565355821395054592

Tips for someone who’s considering making their first board game ever—a Twitter board game design discussion:

https://twitter.com/ell_deck/status/1565338686992142336

5 ways to know when your board game is done:

https://boardgamedesigncourse.com/5-ways-to-know-when-your-game-is-done/