Honestly, some days it's just not in the books....
A couple trips ago I went 4 for 11, doing what I always do, the same hooks. It was my worst day for landing fish all year going back to winter steelhead, and dropped my landing ratio on the year considerably.
Today I went 8 for 9. Same hooks, same hook set, same way of fighting. I think it also has a lot to do with how spunky the fish are. Also has to do with how spooky they are, resulting in them either just nipping at your gear or hammering it. Lots of variables. I find for coho I sit at around 70% landed on a typical year.
Sticky sharp hooks, a good feel, fighting with side pressure, and not horsing them much all help a lot. I tend to fight fish by hand on spinning reels and fly rods, just pretty much loosen the drag off completely and use my finger on the spool to control runs, etc. I find this to be more reliable than the drag in most cases and have lost less fish in the past 2 years of doing it.