Maybe spend more than five minutes and then do something nice
Eh, not everyone comes up with something fantastic right away.. If you ever really get any ideas, sketch 'em out er something. I've only sketched maybe ever 2 of my maps, but it does help in the long run. Good luck!
And then what really helps out any map you make is... lots of time. I speak from experience; I can think of a couple of my maps that would play nicer/look better if I spent another 30 minutes picking at 'em.