What is a general/well-established running advice that you don't follow?

Title explains it well enough. Since running is a huge sport, there are a lot of well-established concepts that pretty much everybody follows. Still, exactly because it is a huge sport, there are always exception to every rule and i'm interested to hear some from you.
Personally there is one thing I can think of - I run with stability shoes with pronation insoles. Literally every shop i've been to recommends to not use insoles with stability shoes because they are supposed to ''cancel'' the function of the stability shoes.
In my Gel Kayano 30 I run with my insoles for fallen arches and they seem to work much much better this way.
What's yours?