How about making some maps?
Pick a spot and just begin. You'll start your flow and you can always backtrack. The game will morph into something completely different by the time you're done anyway.
I think I started mine with the dungeon. I made a fairly rough dungeon to start with, and used it as a hub to get some running around done, and then started working on the town maps, close by. Actually I made a huge world map, but made it mostly water, and then I made an island, then made a dungeon.. made town, then made the dungeon a little more detailed.
Instead of big box rooms, I tried tobreak corners up, or add different kinds of obstacles I didn't think were typical in a game. I also read others advice about not going so over the top and blowing all your ideas in the first dungeon or first boss fight. (I haven't even made database entries for bosses and most enemies I haven't even modified stats). Anyhow I hope some of this helps.
There are several threads over in 'General Discussion' about this, giving a variety of opinions. Perhaps reading through a couple of them would help you decide what to do.
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