Tie this on when all else fails...
 
This bait had proven itself over and over for me. When I've gone through my entire box and nothing seems to work, this always gets bit.
 
It is the ever popular “pheasant tail nymph” fly but designed to be used by ice fishermen! (although it would be just as effective for other fishing scenarios).
 
Tied with a 3mm tungsten bead on a #12 chemically sharpened hook, this bait falls slowly, but still is very fishable in 20+ feet of water! Sometimes less weight is better as it gives the bait a more natural appearance. 
 
Order some up to be ready when the bite gets tough