"Gotcha" tips

There are some great guides here for beginners and troubleshooting. I'm wondering if there's any resources for the "that would have been nice to know" stuff? Things that seem obvious to an experienced printer but might not come to mind for a newbie?

Examples: Adjust your fan speed and/or print speed when printing smaller parts; use (X) type of support with (Y) settings when printing Z type of supports (I'm still trying to figure out what X and Y are for my particular Z); here's when you might want to change the angle of your model; etc. Those are likely overly specific, but basically I'm trying to find tips that might save headaches down the road.