Sometimes adhesion to the plate can be an issue, and as such there are certain slicer settings that can result in a easier time printing. There are three types of detachable adhesion aids which are skirts, brims, and rafts.
Skirts are the simplest and fastest type, this type does not actually increase bed adhesion, and instead primes the nozzle and removes any piece of filament that may cause an issue later on. The majority of the settings on this page do not need to be changed as they do not affect the print adhesion.
A brim is a single layer around the print which helps increase the adhesion by increasing the surface area in contact with the print bed. Here the brim should be on the outside as that will help with the removal of material and the brim width should be within 5 - 15 mm. Anything less than this results in ineffectiveness and more than that is unnecessary.
A raft is exactly as it sounds, it creates a entire bed of filament on the bottom of the print which is then used to print the part. This results in the most stability in the event of a very thin and narrow object, but keep in mind it could be difficult to remove the object from the raft if the air gap is too small. It is recommended that the raft not be used as it is unnecessary for PLA prints. If it is used then a reason should be included stating why the raft is needed. A brim will work for most other needs. More information on build plate adhesion can be found here.
