Long queues usually arise from one bottleneck: everyone arrives at the same time and there is only one check-in point. Agree on arrival times and give VIP guests and speakers a separate entrance. Set up multiple check-in desks and split guests by surname or ticket type.
Self-service kiosks with QR scanners speed up the process enormously. Make sure your wifi is reliable. One faltering connection brings everything to a standstill. Test your entire check-in process the day before with at least ten dummy tickets.
Read more tips in our article on registration and check-in at your event.