I think the important thing is not to get discouraged (easier said than done I know) and to vary your location and techniques, and keep mental notes for future use.
I blanked the other night fishing at the same spot, bait, rigs, distance and the same state of tide that I caught six fish on two nights previously. Go figure.
My own thoughts are that unless a fish hooks itself we miss a lot of bites that are very timid or gentle. I often have an "is it or isn't it" moment when the rod appears to be moving a little uncharacteristically but not necessarily enough to warrant trying a strike. Sometimes its a tough call...
It's a big old sea and the right place at the right time has a lot to do with success IMHO.
As I've said before, I'd rather be fishing and blanking than not fishing, but it can become disheartening sometimes.
Good luck !