[Early on in the morning, Stiles can be found in the common rooms, setting things up, taping papers and posters on the walls and carrying plates and later on, actual food to the lounge. Maybe you're helping him? Maybe he approached you before about a presentation he wants you to hold, and you're here now to prepare for it.
And later, as the meeting officially starts, Stiles hangs around greeting people, making a list of everyone who's attending, talking to people:] Hey, great, you made it! [or] Okay, I know for sure you need zero help with modern stuff but if you go there, there's free cookies?
[And even later on, he's finally hanging around in the room about the movies, waiting until everyone's in, and.]
Okay, so-- Lord of the Rings: Fellowship of the Ring, the first of the trilogy! Timer.... at the ready! [Yes he has an actual timer to keep it under three minutes.]