1.Keep your flies sharp.
It goes without saying that a sharp edge on a knife makes a huge difference in the field. Fly hooks should be treated with the same respect. Consider how often they bounce along rocks, get caught up on branches, or even thwack the concrete bridge supports. It's worth carrying a small sharpener to keep the point sharp enough to pierce the hardest of fish mouths with the least amount of effort.
2.Stronger Tippet.
With today's advanced tippet material, this has never been easier. Small flies call for smaller diameter tippet, but use the strongest you can. As a general rule I almost never go less than an 8 lb fluorocarbon tippet when I'm fishing somewhere large fish lurk. But who ever knows, large fish can be anywhere. Don't be caught under-gunned.
3. Know your space, have a plan.
Before fishing a certain run, riffle, hole or otherwise, take some inventory. Check where the hazards may be. Tree roots, boulders, or inaccessible shoreline can all be thorns in your side when trying to land a big fish. Have an idea in mind so when you hook that fish you know where you need to go.
4.Check your line
We've all done it. Catch a fish, or three, then toss the fly back out there and break off on the next fish. It pays to check your tippet after each fish to make sure there are no nicks or weakened knots. From top to bottom, check it all. Make it a habit to check and re-tie after a good tussle or snag.
5. Keep it short.
I've often realized that the more fly line a fish has taken from the reel, the higher the chance of the hook coming out. Especially with heavier lines and small hooks. All that extra weight doesn't play in your favour. So keep casts short and move into position to make the shortest cast with the least amount of mending across seams.