I have enough clothes so I can go for the week without doing a load of laundry - about 7 each of pants, long sleeve tops, short sleeve tops, camisoles (instead of bras), underwear, socks, tights. I have two drawers for these items. Then in my closet I have a basket for sweaters and about a dozen hangers - a few "fancy" dresses and nicer, blouse like tops, and I think again maybe 7 skirts. I don't have seasonal clothes - the short sleeve and lighter weight stuff gets worn in the cold weather too, just layered with longsleeves, sweaters, and tights.
I pretty much only buy used clothes, so my turnover rate is a bit high. My rule for myself is if I buy something new everything still has to fit in the spaces I have, so that means something old ends up in the donation box. This makes a big organization unneccessary. At this point too I am starting to know myself well enough that even if something catches my eye I can tell if it is actually something I will wear. I know I won't wear certain styles and fabrics, nor will I wear things that need more upkeep than throwing in the washer and hanging on the line. So I basically have very similarly cut khakis and corduroys, cotton skirts, similarly cuts jersey tops in various colors, and wool cardigans - practically a uniform. This isn't terribly stylish, but it is practical.
When I do a big purge, bi annually usually - I make three piles - clothes I definitely wanted to keep, clothes I wasn't sure about, and clothes I definitely did not want. The keep pile got divided into seasons, while the maybe pil went into a box in the closet. If after a month or two I could remember what was in it I kept it; if I couldn't it all got donated. Generally I never remember what is in the maybe box.
Have you seen the Brown dress blog? This women made a dress and wore it every day for a year. I was never much of a clother horse but even so I found the idea inspirational. Freedom from the feeling of needing to have lots of stuff - including lots of stylish clothing - is such a nice thing!