Well, if you're deciding on going to a concert, you might want to get Meet and Greet passes.
(If you don't know what meet and greet is, it's basically when you meet a certain celebrity in a room after a concert. Meet and Greets are also very pricey.) For a less expensive way to meet them, wait outside the arena, there would usually be a large group of fans, waiting for them to sign autographs.
Hope that helps!
( Remember this only works if you're going on a concert!)