The most effective, easy-to-use strike indicator I’ve ever seen was an aluminum flip top from a beer can. I saw this demonstrated about 25 years ago at Put-n-Take Lake while fishing with my then 7 year old son. In addition to the flip top, you will also need an RV comfortable enough for a 3 month stay at the aforementioned fishing hole/campground, beer, your favorite nylon-webbed, aluminum-framed beach chair, a Mitchell 300 spinning outfit or equivalent, rod holder (preferably hardwood, sans bark and leaves) a hypodermic needle and a couple of good sized chunks of lead.. The procedure is as follows:
1. Strategically place your nylon-webbed, aluminum-framed chair a short distance from the refrigerator in the RV and within casting distance of the “lake”.
2. Open a beer; save the flip top.
3. Guesstimate the height of the weed bed at the bottom of the lake. From the hook on your line, add a fair amount of lead at a point equal to the anticipated height of the weed bed plus about 6 inches.
4. Fill a good sized nightcrawler with air from the hypodermic needle and apply to the hook.
5. Without spilling your beer, cast to the spot most recently stocked with fish.
6. Leave the bail on your spinning reel open and place it in the rod holder.
7. Bend the flip top from your beer can and hang it from the V-shaped slack created between the open bail of your reel and the first eye of your rod.
8. While reclining in your chair and as the nightcrawler floats 6 inches above the weed bed, watch for shrapnel in the shape of a beer can flip top as it slingshots from your now taut line. This indicates a strike. Protective eyewear is recommended.
9. At this point you can choose to either close the bail on your reel and play the fish or, do as the guy I observed did; let the fish swallow the nightcrawler down to its *** while getting another beer.
I have no idea how this applies to fly fishing, but I can’t think of everything.