Yeah water is good, but never make a lake too large, because around of it you can´t walk anymore.

Also if you make a lake too long, then it happens that quite large areas will unpassable, also if you want to walk there near the water.

If you want to make a river: One part of the river should at least be always in the south part of the map.

A river should always be from one end of the map to the other end (from east to west).
Never build a river, which origin is anywhere in the map and is not from east to west, from one side to the other.

Coastlines should be in the east, if its possible, what I know.