crickets?
unless there's been a very hard frost, try crickets under overhanging trees, bushes, etc., or just next the bank, or other good cover. don't grease the tippet because it's better if it sinks. crickets last for quite a while as fall goes on, and they make a big tastey meal. my own preference is a Dave's Cricket with the legs pulled out to the side so they really show up. caught one of the biggest browns of my short angling career on a cricket floated over an 8 foot deep hole which i could see to the bottom of.
fly fishing and baseball share a totally deceptive simplicity; that's why they can both be lifelong pursuits.