[@Gareth] Most of the time I find a good description of an area is fine. Theater of the mind is a powerful thing, and you really don't need to pin down where every little detail in a scene is. This is especially true during fight scenes between powerful characters. obstacles like walls, furniture, etc will not impact them too greatly. Having said that, I do occasionally find maps to be a good aid if there are a lot of characters in a scene doing very specific things. It helps to keep track where each little thing is playing out, and helps everyone visualize the same thing. This can be a detriment sometimes, as having a map to look at can restrict decision making. Players are suddenly basing their choices on what they see VS what's been written in the RP. 

Maps are one of those things I tend to make myself, but don't want to spend a lot of time doing. There are a lot of services, but I personally enjoy using dungeon draft to draw up little arenas for the characters to be in. If there's a downside, most of the included assets are for a fantasy setting, and most of the free tile sets are a little uglier than they need to be. If you want something pretty, you'll have to learn how to draw or pay for premium assets. If you want to make something more like a world map, I've made a few of those freehand in image editing software. There are lots of tools, it really boils down to personal preference and how much you want to spend.

As for my creative process, I usually just visualize what I want in my head and then consider how I'd go about making it. Once that's taken care of, I concern myself with making it look presentable. But only if time allows. Posts are due once a week after all.