Mouse Ears

To make sure your model stays on the build plate.
Instead of a "brim", "skirt", or "raft" If your slicer cannot make them for you.
If the bottom surface you get on your model when you print with out a raft is good enough (sometimes I do like what the raft gives me on the bottom of my 3D prints) and you don't want to use the time and filament to print a brim all the way around your thing, use these "Mouse Ears" scaled and positioned as needed to provide better adhesion where it counts.
I scale the height of the ears to 2 layers, and pause the print after the 3rd layer to tape down the ears onto the build plate with appropriate tape (often masking tape as with PLA I do not heat the plate to more than 30°C) then resume printing. the Mouse Ears will hold the corners -or edges- down so the thermal contraction upon cooling does not loosen the print from the plate.