Plotting is fun. Play with your characters (and your readers), plotting dastardly things to do to them, have them do and say. I love doing a brainstorming session with writer or reader friends. Don’t discount anything at first. The more outrageous the better. Let them percolate for a while and see what the girls in the basement come up with.
Make a list, as long as possible. Cliches and hackneyed ideas are easy to come up with. The more original and freshest ideas come further down on the list.
Take your time over it. Preferably, plot your next book(s) while you are writing, editing or resting an earlier one.