I'm doing something I've never done before.
I have a sheet of hex graph paper. I am filling it with weird things, many of them generated randomly.
Things on the map include:
A clan of circus gnomes in rafts.
Three separate halflings traveling up the river in boats. The second one is named Sam "88 Keys" Clark.
An underwater ogre cave with a spyglass, a silver holy symbol, and an everburning torch. (That last item will make the cave easier to find, I think.)
I thought it would be nice to have a river, so I could put a village I was thinking about making on the river. I spent the next two hours coming up with weird things to be in the river.
Being the DM is fun.