...

Skirt Settings

Skirts are really useful for priming your extruder prior to printing. I generally print with a skirt offset of 4 mm and 2 outlines. However, changing the offset to 0 mm, offers the ability to create a "brim" that will connect to your part and help create surface adhesion. For more information on skirts, brims, rafts, this tutorial is very helpful:

...

# of perimeter outlines for your skirt.

Raft Settings

A raft offers a base understructure that will contour to the outline of your print, increasing the surface area to the bed. This in-turn will offer more adhesion to the print bed. However, because rafts take a long time to print and use a lot of material, it is only recommended to use rafts for prints that have a low surface area with the print bed or that generally don’t have a good base will often benefit from a raft. Also, whether due to the design of the printer or calibration, those users with beds that are slightly uneven have often found that rafts can provide a good foundation.

...