Brown hair mostly. Length and type doesn't matter but the color. Eye color preferences; steel grey, light grey, dark grey, blackest of darkest brown, amber (not to be confused with brown btw) or pale green. High cheekbones, jutting or prominent chins, strong jaws (in my males) and the annoying compulsion of always creating caucasians, i.e. white folks.
Which is why I have purposely changed my creation habits. For instance, when I recreated my gay couple from Sims 3 I made one of them men of a cuban/russian descent and gave him features that displayes that. I also softened up the facial features of his mate. I have also favored game created townies that are distinctly not caucasians and I have several households of townies that I have housed in my main save for that reason. I have even gone gallery diving when populating some saves.