A couple pictures of some friends fly fishing for salmon in Alaska
Casting slightly up and across will give your fly time to sink a little before the swing. I find that on the when the fly just start to swing i get most of my takes. When fly fishing for salmon in stronger currents a heavy fly and or a sink tip is recommended but is not necessary in situations. I will choose which size of fly rod i will carry after I have chosen the size of flies that I will be using for the days fishing. All Salmon have strong mouths and some weight to them so when you set the hook make sure you set it like you mean it. For the most part you will have a strong enough leader for the fish you are pursuing and in glacier tinted waters you don’t have to worry so much about them being line shy. Beef it up and set it with authority.
Wading in glacial waters can be difficult because of visibility. A good rule is never wade more than knee deep while you are fishing. I find that this keeps me out of trouble with the deceiving currents and it also allows me to recover faster if I do go down.