When writing novellas and novels there are two primary writing groups. Pantsers, who simply write allowing the free-flow of ideas on paper/document. The other group is the Ouliners who plan out each scene and chapter with some detail.

I have a question for each group:

Pantsers, how do you rein in your characters, or do you end up re-writing when they go far afield?

Outliners, do you allow your characters to tell their own story, or do you follow the outline exactly?

Later, I'll offer a third option in my response.