Clouser Minnow Fly - Choice of saltwater or freshwater hook and size.
Unweighted flies with bead chain eyes. Flies are tied with synthetic fibers that repel water, so they're as fresh at the end of the day as your first cast. Extremely durable. Tied with a little extra fullness so you can trim to your liking. Use a small mustache comb if they get too mangled.
Fish for Bonefish, redfish, snook, great in the flats - Bill even uses them for Bass fishing. The Clouser fly is an all-around great universal fly that should be in your tackle box.