Naturally, I prefer to avoid writing appearances overall and use a picture to describe my character(s). Otherwise, I usually opt for noticeable features rather than writing an entire appearance. You can have two brown-haired humans with blue eyes in a RP, but what makes them distinct from each other? Are they lanky, muscular, obese? Is their skin embellished and smooth, or rough and gritty with deep groves? That sort of thing. It may sound like what you were doing before, but in my opinion, the finer details make the character.