Upturned corners, strings, and prints that look like they're melting.

[EagleSeven]

I keep a long bladed knife handy to push-down those warping (Up-turning) overhangs, when they start.
(Push them a little Past level, then they spring-back to level, before next layer is extruded)
I call it 'High-speed Sculpting'

[TiredJuan]

This might be a good way to get a fan shroud printed (so I can again print a better shroud.) Thanks for the tip.