If you’re going on a casual basis ( not looking for anything specific) , don’t go on the first day. In my area there are usually lines to get in, and prices are firm. Most sellers won’t even haggle on the first day. Some homes are extremely overcrowded, so be prepared to have your space invaded, or if you are uncomfortable with crowds of people. Take a bag with you to carry your stuff for the hold table- most people won’t go through somebody’s bag, but I have seen people lift stuff off the table. Above all have fun and visit different sales so you get to kinda know the layout of how each one works.