What is working well for us is to connect with people online before the event. Often LS sites will have an 'event attendees' list and you can send some notes to select folks beforehand:
"We noticed you are planning to attend 'Foo Bar Blitz' this Saturday. We're a little shy and looking to make some new friends. If you notice us, we'd love it if you stopped by to say hi, and we hope you won't mind if we do the same."
Adding a specific note about what attracted you to their profile may help prime the pump.
Keeping a mental track of who you contacted so you have some prepared conversation ideas in the can may help as well.
Good luck!