One of the more pleasant aspects to trout fishing at this time of the year is the way things change throughout each 24-hour day-night period. If you know their habits your catch rates rise.

In the trout streams, flows at this time of the year are generally slow, the water clear and the fish easily spooked.

During much of the day the fish lie under shadowy banks, hidden in rapids or deep in weed beds and sight-fishing with a fly or lure can be hard.

A lot of it is chuck-it-and-chance it, hoping that you have put the appropriate goodie in the right place to bring Mr Salmo out of hiding.

A careful approach is essential. I've seen fish bolt upstream or down when I have still been a good 50m away; they have superb eyesight and survive on the strength of it.

You can minimise the risk of scaring fish in a variety of ways.

Firstly, you are often better off getting into the stream than walking the banks. In the water you are lower down and less silhouetted and if you always head upstream, you are in the one blind spot that trout have as they normally face into the current and cannot see immediately behind them.

Secondly, pay attention to leaders.

If you are lure fishing, especially with braided line, use a fine mono leader. Fluorocarbon is preferred because it has a similar refractive index to water and thus in theory is nigh invisible.

Fish still know it's there, of course, as they can detect anything that is in the water, but at least you have less chance of spooking them than if you use braid straight to the hook or thicker monofilament.

Smaller, rather than larger, lures also are preferred as they make less of a disturbance when they hit the water and are less likely to snag on weed or the bottom. You can also retrieve them more slowly and manipulate them more easily.

Compare, for example, a small No 1 Celta or Imp Spoon and larger versions of the same lures such as a No 3 Celta or a Wonder Spoon and watch the difference.

Fly fishers can benefit also by using finer and longer leaders. A 3m leader is standard for most fishing but on low, gin-clear water I move up to 4m, 5m and even 6m leaders.

It takes a little extra casting practice to learn to use a long leader but experience has shown that it pays off.

There are other little fly fishing tricks you can employ on low water.

Knots, for example, should be as small and neat as possible, to avoid distracting or scaring fish by creating a vee in the water during retrieve.

Make sure, too, that any knot between the leader and the tippet is well away from the fly – the further away, the better.

I've also learned to make-long distance casts – again the further the better – and to keep casting movement to a minimum.

Forget about false casting, it's a waste of time and you don't need to do it. Use the latent power of your rod and simply pick up the line and put it out on a single cast.

Minimal movement, minimal scaring of fish, maximum hook-ups.

I'm a bit of a heretic when it comes to the matter of camouflage because I have yet to be convinced that it makes a lot of difference.

I have worn all sorts of different coloured clothing over the years, some dull and dark and others outrageously showy.

I've also used a variety or rods, some glossy and shiny, others dull or camouflaged, and I am still unsure that any of it makes a significant difference.

The important things I rely on are careful movement, upstream wading, fine long leaders and delicate presentation.

Curiously enough, I have learned to pattern myself in part on a cow. I noticed many years ago that cows feeding along trout streams did not seem to bother the fish unduly, probably because of their slow, deliberate movement along the banks.

So that's how I move, ambling along slowly, watching ahead for Joe Blakes (snakes) and convenient places to enter and exit the stream, as if I was just another of the permanent bovine residents presenting no danger to the fish.

Remember, too, that despite the fact that fish are hiding during the day they are still alert to food landing in the water. In practice, that means if you put the right goodie in the right place you should get a reaction from the fish.

So work out where the fish are most likely to be and put at least your first and best cast in that position. It's an old but true adage that the best caster gets the best fish.

Make a bad cast or poor choice of position and you may scare the fish and not get a second chance at it.

Right now we are in the middle of grasshopper season. This is great fun fishing, with about 12 different hopper fly patterns to choose from.

The fish are attuned to the hoppers landing on the water and as soon as they sense the splashdown or a few kicks of the legs they are after it like a bullet.

It's exhilarating fishing because you need fast reactions to match the fish's behaviour and achieve a hook-up. Strike too early and you miss the fish; strike too late and the hook has been spat out.

Timing has to be perfect in the hook-up but, curiously, the cast can be quite clumsy. In fact many good casters deliberately bang the fly down hard to attract a fish's attention, especially when it is looking the wrong way.

Of course, too, you can always cheat a bit by berleying a run with a hatful of live grasshoppers with your artificial in the middle of them.

Lake fishing is different from stream fishing. A common pattern is for the fish to feed early in the morning, then go deep during the brightest and hottest part of the day.

The fish search out their favoured thermocline – the temperature zone where they can most easily extract oxygen from the water – and they stay there for most or all of the day.

Late in the afternoon, or more likely at night, as the water cools they head back to the surface to feed in the shallows.

Bait fishers can capitalise on this by fishing the steeper banks and deeper water rather than the shallows during the day, then the shallows at night.

Trollers during the day need to go deep to get lures to within striking distance of the fish.

Lead-core line is a preferred option for ease of use. With five colours of 8kg lead core, a lure can be trolled about 8m down but to go deeper, a downrigger is required. Currently many of the fish are around 8m to 10m down so both techniques can be effective.

Fly fishers might have a tough time during the day unless fish are up feeding in wind lanes where food has gathered, or if there is a hatch of insects or a sudden burst of grasshoppers.

Most prefer to fish at night, when the fish are cruising the shallows searching for drowned, drowning or hatching insects or mudeyes hunting their own food.

This can be fly fishing at its most exciting best, especially when you cast out into pitch darkness with a Craig’s Night-time, Mrs Simpson, Taihape Tickler or Bryan Pratt Mudeye and are met with a thumping great strike and a big, tough fish leaping and crashing around on the surface.

Your heart is in your mouth until at last you bring the catch to the bank for capture or release.

And that was all because you learned to read the ritual of the daily routine of trout as they change their behaviour to suit the circumstances of light, food, temperature and oxygen availability.

Learn about these basics and your fishing should be eminently more successful.