When you are on a long run that no one knows you have to run some stuff blind. Otherwise you will never finish the runs. So here are some of the things that we learned.
First, know a little about the class fives on the run. We knew the runs had them and we found out before hand what to look for so that we wouldn't find ourselves in the middle of them without a scout. Some of the other rapids had class five stuff and sure enough we found them by mistake, but we were able to minimize blind class 5 exposure. It happens, but if you have some knowledge you can usually spot the big stuff coming up
Second, if you can see an eddy anywhere below a lot of times you are gonna run it, without knowing what lies between you and the eddy. Time on these long runs just doesn't allow you to see everything. Our experience was that if you could see the river below you, even if it was way down there, pretty much just keep going
Learn some hand signals. Typically best paddler runs first and will signal back to the others. Its just to let you know if something really big lies between you.
You will occasionally find yourself in the wrong eddy or in a bad place. Cope. If there are a lot of rapids that are way out of your league or a lot of bad spots, then you really should have a guide on that run anyway.
Best days ever on the river are when no one in the group has done it before. Getting lead down sucks. But it does take a long time and it does ramp up the difficulty.