Plans don’t help you finish things more quickly. They help you finish things more slowly.
That’s a very good thing if you have a tendency to make mistakes because you rush. Some people are generally slow at tasks, and other people have the propensity to rush. I’m the latter. I will power through a lot of things if nothing inherently stops me. Plans, schedules, agendas – these things all keep me measured. They keep me from trying to have everything done yesterday.
You’d be surprised how often you actually want something to take longer. Ultimately a lot of things don’t really have a time they need to fill at all, but you can certainly give yourself a lot of stress by trying to do too much in a day.
So plan for a week. Write down the steps. Be happy with them, and then be satisfied enacting them. Plan to be slow.