If you don't have a timer, run out and get one now!
This is my new one. I wore the old one out.
I haven't tried it out yet but I'll let you know if I like it as soon as I've given it a whirl.
If you're thinking of getting a timer, try to find one that will time to more than 99 minutes and 99 seconds, i.e. one that will time hours.
I'll mention my timer many times on this blog, I'm sure.