Start with the engine trimmed fully down. Get the boat on the plane, then drop revs to an economical amount. Now trim up the engine slightly. As you trim up you will feel the helm go lighter and the tone you hear will change. If you raise it to far the steering will go skittery and then you will loose drive as the leg comes up to high.
It’s best to trim up by one or two taps on the button at a time and then see the results. You should also notice your speed slightly increasing as you reduce drag.
If you find yourself about to cross some wash trim back down momentarily. Likewise if you plan to take a sharp turn trim back down for the turn.
If at any point you bring the boat of the plane or to a stop then trim back down before revving up again.
The above all assumes straight line blasting in reasonably flat water. If you are operating in a bit more sea state then basic principles are; - trim the bow down when going into a head sea, so that the sharpest part of your V hull meets the waves and cuts through them, this also increases your water line length and ensures that as your bow lifts over the crest of a wave your are not caught by the wind. In a following sea the opposite applies, trim the bow up so that you don’t burry the bow into the back of the next wave as you come down the front of the current one.
When you trim the engine up far enough the trim tone will change and you are now tilting the leg (rather than trimming). On most engines the gauge on the console is only for trimming, once you are at the top of the gauge you are now tilting. Engine tilt is for beaching, maintenance, very shallow water, some trailers etc.