As the saying goes, practice makes perfect. Above all other tips, just get out and shoot in the pre-season. Find a clay skeet shooting range and go after shots you might see while on the pond (crossing, incoming, etc.). Ask an instructor at the range for advice or take a lesson. Begin on a less challenging station until you master it. An instructor can offer guidance on proper mounting, how much lead to hold, and following through. The more you shoot, the more comfortable you will become with your shotgun.
2. Invest in a Fitted Shotgun
Many hunters don’t take advantage of shooting a fitted shotgun. If you buy a gun off the rack without concern for the pull length, drop at comb, and pitch measurements, chances are your shotgun will not fit properly. Instead, purchase from or take your favorite gun to a gunsmith who can help you get the right fit. A shotgun that is customized to personal proportions is far easier to swing, target, and take down birds.
3. Toxic Loads
Steel shot loads have drastically improved. Choose a premium non-toxic load. Today's high quality steel loads are fast and have plenty of power to bag ducks cleanly. Beyond 40 yards steel will lose power, so select loads containing alloy-shot of tungsten, bismuth, iron and other non-toxics metals for long range birds.
Test your shotgun's pattern with various loads and choke combinations. Set up a pattern board cover in white paper and draw a duck in the center. From 40 yards back, shoot at the image with your shotgun stabilized in a rest, then try different chokes and loads to see how various combinations perform. Patterning allows to you see which combination of choke and load provides the best performance and to visualize how big a duck is at 40 yard distance. Finally, patterning boosts the hunter’s trust in the shotgun’s ability.
5. Don’t Compute Lead
Sure, you do have to hold the right lead time to hit a flying bird. But there are far too many changing variables (distance, direction/angle/speed of flight) too analyze each situation. Thankfully, you can count on your internal instinct to determine how much lead is needed. When tracking a bird, a shooter should use the shotgun barrel as an extension of his line of sight. If you have a proper gun mount, holding the lead will come naturally.
6. Slow Down
Rushing shots is one of the most common mistakes an inexperienced waterfowl hunter can make. Take your time and make an effort to ease into mounting your gun, tracking your bird, and pulling the trigger. Jumping up and firing at a flock of birds is a guaranteed way to end up with nothing. Wait for the flock to be in the right location before slowly rising to your feet and firing directly at a single bird.
7. One at a Time
Beginners often get excited and shoot into the flock at large instead of targeting a single duck. Set your intention to aim at one bird. Rise above by concentrating only on a single bird. The area of an incoming flight is mainly air, so you must to lock in on one duck and stay with it until it drops. Resist the urge to switch targets by staying focused. If and when that bird is hit, move onto a second target.
8. Aim at the Trailer
As a flock of birds comes into the shooting area, do not go for the lead bird. Many hunters have trained themselves to fire at the leading bird, so chances are that your hunting partner is aiming at the same animal. If you choose the trailing bird, you will most likely be the only one shooting at it. More importantly, it will put your gun in perfect the position to fire successive rounds at fleeing birds.
9. Focus on the Eye
Focus on your target bird's eye. Shooting at the whole bird can result in hitting tail feathers rather than a deadly blow. To correct this, focus and aim directly at the eye of the duck. If you cannot see the eye, then the bird is too far away to shoot. If you can see the eye, keep your attention fixed on it, which helps swing the gun ahead of the bird rather than behind.
10. Continue the Swing
Stopping the swing of the shotgun is a sure way to miss birds. You have to follow through in order to bag a duck. Abruptly halting the swing will ruin timing and coordination. Keep the barrel moving after firing. Having good follow-through is key whether you are shooting at fowl or swinging a golf club.