Make a three-part checkpoint
Record the current row or round, the repeat you are working on, and the page or named section in the pattern. If you are halfway through a repeat, write that too. “Row 12, repeat 2 of 4, increase next” is much more useful than “I think I was on row 12.”
Use visual markers carefully
On paper, use a ruler or removable marker to show the current line. In a PDF, use annotation only if it is easy to edit and does not hide the instruction. A stitch marker can show the physical work while a written checkpoint shows the pattern position.
Using SkeinHub
SkeinHub puts a pattern, counter, notes, and saved project progress in one workspace. It can keep the current pattern page and counter state together, which reduces the number of places you have to remember. See the pattern tracking feature and the guide to avoiding lost places.
The best stopping point
Whenever possible, stop at the end of a complete row or round. If you cannot, leave a note about the exact stitch or instruction you reached. A precise pause is easier to resume than a tidy-looking but incomplete mark.