JustDave, gender may be a factor too?
anyhow, for myself: intp. as with aelan, all i own are high heels (of the variety shown below) and only two pairs of sandals. no flats. Wardrobe basics would be black, silver and champagne gold. If i'm going out, it's always in heels, unless i'm going to the beach or somewhere equally casual.
i like them at least 3 inches, tho if they're real pretty, 2.5 will do. nothing below that.