The way I see it, Slice-of-life does not have to do anything with how the creator's life is really like, so you can add things entirely made up, and impossible in real life.
They can have different slants and backgrounds, but they just are people dealing with everyday stuff, and how it is presented. Plot can be background, with the characters making changes. Story arcs can be entered before you realize it.
One main word of warning if you plan on making them. The most well known types of slice-of-life are soapies, and other ongoing shows set around groups of people dealing with everyday stuff. One problem is that people introduce too many subplots. Slice-of-life is the only type of story I can stand which has no main plot to guide it, but it must be properly made. One good example is a nice dark humor one called Something Positive
. (although I must admit the subplot with Kharisma is off normal even for this comic)
Many stories start with a general outline, and the story is directed that way. These ones start out with looking at how people deal with situations as part of their every day life. With these ones, the stories often move at a much slower pace. I have found story arcs foreshadowed ten years in advance. You need a hook to keep people interested long enough to want to read more. For me it is humor. Others have different interests. You also have longer to work things into the story, including expositions and arranging things in a way that do not make then seem contrived.