It' all confidence.
Native steelhead unmollested will eat about anything 90% of the time. If the water has more color fish the 6"ers if clearer, downsize to 4"s.
Worms work, they're a great tool for bait restriction areas too!
One other thing I like is having a different color cheater than the worm body for contrast, but like the first thing I said, its all about what you have confidence in!