Ok, a couple of thoughts.
First, it depends on the characters and the book(s). In a series, the major characters don't change much each book - they develop slowly over time. Secondary characters may change a little faster, and anyone introduced as a major character for a single book (Stackpole calls them 'case characters) may change a lot.
Second, it depends on the type of story. If your story is character-driven, you need to go where the character is going and as they face events let them respond and change in ways that you think that particular character would respond and change. Meanwhile, if the story is event-driven, you may need to do the 'work backwards' method. Even then, their changes have to be at the intersection of plot and character. Keep in mind, though, that if you need a particular change to have occurred by 'P' on the timeline, you can go back and have them hit with things at 'D' and 'K' that force that change or at least get it started.