Because salmons doesn’t feed after they enter the river it's often good amount of luck, and fact that we was at right place and time to catch it. But there are some details which can help you to choice which day can be more lucky of another, and here I try to show you how to choice it.
1st of all – preparation. It’s important to check weather before you go. Heavy rain always help as fish start to move up the river at flood time. Salmon become more aggressive to fight of better places to rest/spawn before water drop, and because of all that they are less careful and more easily apply to bait! Make sure you have all you need in you fishing bag. Few different lines, boxes of smaller and bigger variants of flies (which work last year at this same water where you going now) polyleaders, mono/fluoro tippets, thermometer, waterproof camera, waders, polarised goggles, scissors and so on.
2nd – after you come on water, before first cast look around. What colour, temp. and level of water is it? Is there anybody else fishing? Is river go up or dropping now? And match this info. to time of year, your tackle and forecast.
In low water fish deeper site with bobbling, fresh water, and in high levels do opposite.
Try fine fly for fine water (size 12) in places and times where fish can feel secure – high bank, trees at morning and evening time.
In very big flood switch to spinning – you can fish it exactly like fly by casting to another side and let the bait drift around. Don’t be to hurry some times fish take just after your spinner or toby got in contact with water - at time it sink down or you wobblers just start to work - before you make any take of line in. More than that - some times keep your rod high to keep line off the water, and max. slow down drift, without use of reel!
General rule say that warmer water need smaller flies.
Lest say:
Colours change with seasons, but that less important thing, and absolutely opt to you e.g.:
Leaders: should be long
Lines: at very beginning of year try some fast sink one in deep pools then is time for Inter and Float, which can be good with pack of different polyleaders to end of season.
3rd – choice of tackle to the water or river you want to fish
Rods:
And not only length, but action of rod is very important. Softer rod with medium action is always very easy to use, and not only for beginners as many experienced fisherman like to feel cast by all the way to put fly correctly on the surface, to not scary salmon, and fish just after bait get on water!
Reels:
And it don’t must to be light, but it must balance weight of the rod!
4th – don’t forget that salmon it’s a wild creature and need you to be quiet as much as you can to catch it. Don’t wader to deep. Don’t fish pool to long, give it rest, go to another place or take break. Always try to fish gently even with spinning - stop bait just before it hit the water surface. Don’t put your shadow on the water. Don’t fish just after somebody else who keep line in beat for hours. In really busy beats try to be first in water.
But most important of all, do experimenting - especial if general rules falls. Fish square and down the pool. From surface and nearly bottom too. With small fly in big water (but not too coloured) and big one (but light) in low levels. Remember that big and small depends not only of size of hook, but of dressing to – long tail shrimp size 10 can be same long as number 1 hook Stoat’s Tail.
PS. Don’t forget places where grilse show, and if possible fish them immediately from top.
Save about 1m of free line for fish when it take, but strike immediately aggressive ones.
After you hook the fish let them do the first run. Don’t play them to hard as their more likely to jump then, and can gone in second from hook by shaking head in air. Let them go up as current of river will take their power off and let you and the line to rest.
Good luck! :)