Here's my tip, I found this one out through personal experience.
After spending many hours detailing the engine compartment in my car, I decided I'd finish it off with a spray it of quick detailer and wipe it down with a microfiber towel to get the dust off from it's first drive since the engine swap. Well, I bought Quick Detailer and Spray on Wax in nearly identical bottles, and guess which one I grabbed? Yep, the Spray on Wax. Now I've got a ton of white specs all in the nooks and crevices that are unreachable. The engine was slightly warm so the wax dried pretty quickly before I could wipe it all off. So, check your bottles before you spray...