I never stop, I move from task to task, totally at random. Finish one, down the tools I was using without noticing where and start the next task. I always have so many things on the go, that is my life.

I have a thing about numbers...
When filling up my gas tank, I often do the pay-at-the-pump thing. I hate that is slows down at that last dollar, so I often stop it earlier and I try to make the dollar amount be something cool; repeated or sequential number sequence... Bonus if the liter count is also a cool number. Palindromes are my favorite; I like symmetry. Patterns too.
I also order sushi (& other things) in even numbers. Single orders of rolls are ok, they come in sets of even numbers.
I do it, it's mostly for fun and to get a rise out of my friends, or to let them get a rise out if me.
I'm sure I have others.

I don't like wonky collors on shirts or tags sticking out.im very peticuler about how I leave the toilet even if someone else leaves a skidmark.

I clean house in binges.

I have a few obsessive/compulsive behaviors of which I am aware, but I don't let them control me--not all the time, at least. On light switches with two or more toggles, I like all to point the same direction so I won't turn on a light for steps if it means throwing that out of sync. It makes no sense, but that's how it is. I have others, but this is enough for now.

I can't do one task at a time. I just can't. I have to jump from one project to another until they're all finished. Or maybe finished, lol. Does that count?