Lacking a slider bar, and time, you might consider a makeshift system. Paper clips on a piece of wire or string, clothespins work as well.
What doesn't work well:
Tape: it falls off, and often at the worst time
Laying out tickets: They can be knocked or blown around
Post-Its: see tape
me: I don't drink anymore
Yelonutz: me either, but, then again, I don't drink any less