Fly fishing can be all about timing. Here are a few timing things to remember.
Anyone who has ever caught a big hatch just right knows how cool it can be to catch fish after fish on dry flies. Remember afterward to write down the day and time that it all happened along with other details in a fishing journal or elsewhere so you can try to time it right again.
Remember that good casts start with good back casts and good back casts are made with a well-timed stop and a long enough pause to allow the line to straighten. A straightened backcast will load the rod correctly for a great forward cast.
When a fish takes a dry fly, especially in slow current or still water, remember to wait a second or so before setting the hook. This allows the fish to turn with the fly in its mouth and you'll have a better chance of setting it correctly.
Remember to time your fly selection according to hatch progression. Start with a nymph just before the hatch, move to an emerger as the hatch gets started, use an adult while the hatch is in full swing, and look for spinners to eventually fall back to the water well after the hatch.
Keep these simple timing things in mind and you'll hopefully be on the water at the right time making great casts with the appropriate fly and setting the hook well as you catch a bunch of fish.