As you get more confident with 3D printing, you'll want to set up a plate of parts and print them at the same time. This approach rarely causes problems, but you may want to use the nozzle-lift function (Lift Z setting) in the printer settings tab in Slic3r.
Raising the print nozzle a fraction before a travel move is a good idea when you have a lot of parts on a build surface. This technique can reduce the chance that the printer will accidentally knock off a part or shift the print carriage out of alignment.
For some objects and 3D printers, you may find that rotating a part 45 degrees on the platform makes printing easier, reduces warping, and minimizes the possibility of travel moves that hit corners or the edges of parts. If a print fails or has problems, perform this simple rotation, or reposition the object on the bed before changing other settings.
