Here is a little secret : Trout like to eat 'Big Black Bugs". My first choice for when "nothings happening", this generic pattern has saved the day. many times. The SJW's buggy look and versatility (it works great on a dead drift, or striped cross current) make it "the" fly for "fishing emergencies". I tie them weighted. Many anglers swear by a size 8 ; but I like a 10. You can get sizes 8, 10, or 12.