There's only one pear rule I religiously adhere to: party is (almost) always on top (colour, accessories, prints etc.). In other words, 99% of my bottoms (except for a pair of printed rayon joggers, but of course there are ways to draw the eye up even when wearing something bolder on my lower half) are plain(-ish) and darker than the tops. I think it makes enough of a difference to my proportions to be the one and only guideline I really stick to, because I tend to feel best in outfits that follow it.