Hi Ema,
attendance recording upon course login could be one possible option.
In our praxis (www.umb.sk) students do not work with computers at all courses, they usually set their attendance afterwards (or 'a posteriori'). Their 'Moodle' presence is sometimes verified against paper presence sheet they sign at each seminary.
Also it would be good to implement this - enable recording attendance of past sessions, when students were not enrolled into the course at the time of sessions.