The usual rule is to develop a uniform - a few basic colours, a few basic cuts or silhouettes, and just keep replacing with same, or buying in multiple colours, so that you can keep it simple. One basic cut for pants; a basic skirt shape, a basic dress shape, etc - whatever flatters you most. If you're a creative type you'll probably want to stay away from yuppie/preppy styles. One book in the library I found particularly helpful for building a basic look was French Chic by Susan Somers. Also Simple Isn't Easy by Olivia Goldsmith and Amy Fine Collins. And then there are books that list different colour schemes, and different dressing styles. You can get a lot of good ideas from these, or you can just get confused, depending. Basically, every article of clothing says something, so you need to ask it/yourself if it's you or somebody else. I really don't think there are any truly neutral looks, regardless of what some of the books say.
If you need dressier shoes that are comfortable, ECCO makes comfortable shoes that sometimes look nicer (depends on the year, unfortunately). If you can find them in your area, check them out.
Unfortunately, looking good does involve spending at least some money, because you need to be able to experiment and you can't do that if you can't afford to make mistakes.