Salmon fly fishing is considered to be performed with heavy two hand rods. Well in most cases. But is double hander always the best choice?
I carry always at least two rods with me. Depending on the river where I fish they range from a 14-feet doublehander to 9 feet #6 single hander. For example in early season with slightly high water I might leave my single hand rods home and double up with two two-hand rods. I rig the other one with a heavier sinking line and the other with a floating/intermediate. On normal summer water levels I always carry a double hander and a single hand rod. Only time when I don’t take double handers with me is when fishing small rivers (for example northern Norway or Iceland). I might fish with a switch rod if the smaller rivers have big enough pools to make it work.
Double handers are perfect tools when fishing medium-to-large rivers (or pools) where you need to cast constantly 20-30m (or over) and cover as much water as possible. Matched with a proper shooting head, skagit line or a spey line you can minimize your efforts and use less energy (and casts) to get the fly where you want. The only down side is that with long rods and heavy lines you loose some accuracy and feel. You should also think about the most likely catch. If you know that 90% of the salmon in the river are grilse why go for a 15-feet 10# weight? You don’t have to downsize to single hander, but maybe a 13-feet #6 weight could do the job and you’ll have heck more fun.
With the single hand rod I can cast dry flies and do maybe some hitching as well. I love the accuracy and control gained with single hand rods. If I need to fish with special techniques, for example strip the fly actively or cast upstream and control the drift I prefer to do it with a single hand rod. With dry flies, no question, only way to go is with a single hand rod.
Best advice I can give is that practice your casting and get to know your gear. When they feel like an extension of your arm, you’re there. You don’t have to think about casting, just concentrate on the fishing. Also, learn to cast from both sides especially with double handers. If casting from your non-dominant side feels totally awkward, learn to make a backhand snap-T or something else.