Of the three examples I would say the bottom one looks the best, but maybe increase the softness/size a little so it's not quite so sharp a stroke. If you want to go an extra mile then use mask layers with a softer brush and experiment brushing the edges of your shadows so they're softer where they touch the light and darker in the depths. But overall the quick techniques you applied do make a marked improvement in my opinion.

As for all the other stuff, yeh it really depends if you have the time to commit (or even want to). The more time you spend on a map the better it's gonna look, if you want something quick and easy then you're process works fine enough. If you want to develop your map making to make your final maps look better then you need to spend time on them.

For my own maps (I play VTT) I have some that are literally just quick sketches and, for a map, they work fine, but they stay locked up in private Anything I put out there, personally I want to make sure it's as good as I can make it.