When fishing upstream, what is the technique for recognizing the strike? Sure, if there’s a surface take or a flash we set but otherwise should I be watching the nail knot?

I have started swinging soft hackles and am new to this fun brand of fly fishing. Despite lots of hits, I struggle to hook fish. (Mostly 10”-14” bows) I have tried both split second sets and the long, let ‘em eat it steelhead method with inconsistent results.
Any suggestions?