Fly selection

Everyone has their own favourites but if you’re stuck you shouldn’t go far wrong with the following.
Early season Olive quill, Greenwells, Rough olive, Adams, Black gnat, Blue Winged Olive, Kites Imperial Sizes #14 #16
Late spring Adams, Beacon beige, Blue winged olive, Black gnat, Elk Hair caddis, Hawthorn fly Mayfly, Grey WuIff, Spent Gnat, Pheasant tail, Red Spinner, Sherry Spinner, Double Badger. Sizes #16 #18 (#10 – #14 for Mayfly, Spent Gnat and Grey Wulff).
Summer Black gnat, various emergers, Black ant, BWO, Pheasant tail, Adams, Elk hair caddis, various sedges, Griffiths Gnat.
fliesSizes, this is where/why many struggle, you have to fish SMALL (except for sedges late on) and fine and far off, the fish are very sassy by now except late in the evening when they will rise beside you. #16 is as big as you need and #18 or #20 is better still. You will find times when you need to go even smaller down to #28! They may be hard to see but the good news is that the fish take tiny flies very casually and confidently, don’t strike! Just gently lift into them.
Early season Waterhen bloa, Silver March Brown, Green Lurex spider, Black spider, Partridge and Orange, Greenwells and Snipe and Purple. These may need to be quite large and tied on heavy hooks to get down in the water #10 – #16 Gold heads, particularly Hare’s Ear, will be well received.
Late spring Go smaller with the same flies and start using the Pheasant Tail Nymph.
Summer onwards When nothing is moving on the surface don’t assume nothing is feeding. If you are up to the short line upstream heavy nymph technique using Czech nymphs you may be in for a surprise.
For Peter Radford’s  simple guide to fly selection through the season