This is honestly just a matter of preference.

Some people find it easier to plan a replay in advance, sometimes thinking out basically every single move beforehand (cough NutHug cough)

Personally, I don't do that much planning at all, besides in the immediate future. Say you're hitting uke, but then parts of his body go flying away that you'll want to hit later. It's a good idea to edit that hit so that the body parts fly to a more convenient position. Otherwise, I just look at the ghost, mess around, and if it looks like I'm going to look cool I roll with it.

Certain types of replays take lots more planning, and I think realism replaymakers do a lot more thinking ahead than I do.