I didn't mark them an don't really see a reason to. In the pattern I don't really want to focus on some little mark to determine flap position. Time and sound suffice.
At the perch, reduce throttle and lower flaps for a count of 3 and a quick glance at the flaps to see the position. You'll be able to tell if they're a third deployed without marks. Turn base, another count of 3 and another glance. Turn final and lower the flaps until I can hear the flap motor sound change indicating full deployment. Nuthin to it.