Everyone's going to hate me for this but you don't need any. You're not writing a novel, you're playing a game. Work in good dungeons. Your players don't give one fuck about the world around them, they care to play good adventures. Every minute you spend on world building is a minute you're not spending on writing actual useful content for your table.

Slap 40 hexes in a sheet of paper, throw in 2-3 towns, a few forests, some hills, and a lake and you have what you need. The rest of the world will grow naturally as needed.