My advisor's recommendation for dealing with the overwhelming size of My First Conference was to contact potentially relevant people for individual meetings. This is rather more intimidating to me than a conference of 8,000 people, so I attempted one, and otherwise just attempted general networking.
My one meeting may or may not be considered a success. The professor didn't have a schedule planned, and suggested I come up after one of her talks. Naturally, of the four talks she was giving, two were during my posters, one was during a formal student lunch, and the last was right before one of the posters. I managed to avoid any stress over this by visiting her students' posters; she's the kind of professor who shows up to support her students, and I managed a quick conversation with her. This let me off the hook for trying to come up after a very popular talk. It was just a quick conversation, but I introduced myself, and she even asked if I was planning on doing a post-doc and whether I'd consider applying to her university.
My other formal networking attempt was the formal student lunch, which was a small group of a students and one "non-traditional" PhD in the field. This was the first opportunity I've had to talk to a PhD in my field who went into industry. I definitely got a good feel for what that career path is like, and I got to have the best cheesecake I have ever tasted. But, it did more to solidify my plan to go into teaching than to move me back toward the non-academic options.
Informally, I made some networking attempts at the pre-conference teaching institute. I chatted with people at their posters and at some round-table discussions. I even made myself send some follow-up emails the day after the conference (since I didn't have to spend the day traveling). I don't expect anything to come from any of these contacts, but they certainly made the conference more bearable.
Overall, I think just attending the poster sessions made the conference seem smaller. Yes, there were 180 posters at each session, but there were usually only 10-15 in any given sub-field, and never more than a half dozen that seemed interesting to me. It was easy enough to get the presenter's summary, and see if I could come up with a question or two. Even two minutes of one-on-one conversation in the crowd seemed like a healthy interaction, and a vital break from the endless hard-to-process research talks.