Mental constipation is a bitch.
Fighting Fantasy is not a setting. It is a series of unrelated stories forced to live together, the act creates tension. The tension is where the game is. Bespoke settings lack this, replacing it with accidental or deliberate synergy. Tension resolved, game less fun.
Mechanics in games should be be tidy. Individually beautiful. One should be able to look at the interlocking system and appreciate how pretty it is but also how to take it apart.
Copyright is very complicated. Handle professional advice or discussions of morality by ignoring it when it gets in the way of a good idea.
Settings should leave gaps. The space between places is magic. Maps are inimical to exploration.
Ignorance is fun. Game from the position of an outsider. Create a setting from the perspective of unravelling a strange and dangerous world. Give them Sigil, the literal hub of the wheel, and let the centrifugal action of curiosity take them outwards. Make the experience magical by being ignorant of the truth. Create as you go, focus down to the ground and ignore the big picture. As you explore more elements are added that do not fit. Tension is created.
Point buy systems are terrible.
Death is less fun than an ignoble retirement.
The best dungeon is a room with a box that says "Do Not Touch"
An atmosphere of lightness is lubricant for running your mouth to interesting places. Jokes are often genius creations. The desire to create laughter in others makes us create harder. Horror is funny. Transgression is funny. Horror games aren't real.
Jokes live or die by much harsher standards than precious dour creation. They are therefore stronger.
Have a healthy disinterest in tempo. Genius appears in the gaps.
Don't publish a setting. Publish how you arrived at the setting you didn't publish.
Any novel is better and more useful than a setting book.
Separation of player and GM is desirable. Either side of the wall tends its own garden.
Selling RPG literature is hard. It is much easier if you don't count and pay more. Marketing is a colonial invention.
Is wearing armour a skill?
Blaaaark. Ok, I'm done.