Shotguns can be really fussy about their loads. Every shotgun barrel has loads and pellet sizes that it "likes" and those that it doesn't. Sometimes the differences can be dramatic.
If you decide to try a new shotshell brand, load or pellet size, you should check it out on the pattern board. Probably most loads will look pretty good at short range, but at longer ranges, you might see very different pattern results between different loads and you might pick up a bit of additional range with the right load.
Always wear hearing protection while shooting your turkey gun to avoid permanent ear damage and hearing loss. The muzzle blast of a short-barreled, magnum turkey gun considerably exceeds the threshold of potential ear damage.
Bows are even more finicky. Change one little thing, such as head weight or design, arrow spine or anything else, and your bow will probably need to be re-sighted. A big gobbler's vital area is pretty small and there is not much margin for error.

Perhaps the most useful thing we can learn from post-season deer scouting is where the deer, and particularly the bucks, end up. If, all season long, you played catch-up (and not too well) on local deer movement and habitat and cover transitions, taking a look right after the season can put you ahead of the game next season.

Don't wait. Get out right after the season is over and take a look. Once the hunting pressure slacks off and certainly by the time spring "green up" occurs, deer will begin to develop different habit patterns and travel paths to accommodate new environmental conditions.

You want to know just where they all went as the season ended. Look for well-used winter trails and other active sign. Try to discover late-season food plants and feeding patterns. Look for late-season buck sanctuaries, which will likely be different from buck hangouts in the early and middle part of the season. By knowing where they went, you can get there first next year.

Perhaps you think it's hard to miss a gobbler's head with a wide shotgun pattern. While filming the "All Stars of Spring" turkey hunting video series, we saw plenty of misses.
Modern specialized "turkey" chokes don't throw a very wide pattern at short range. Under 20 yards, we've seen patterns as narrow as eight inches. That's more like a big bullet than a pattern. Unless your turkey gun shoots precisely dead on, an up-close gobbler can easily be missed.
In the old days, correcting a shotgun's point of impact was fairly difficult, involving bending the barrel and either bending or altering stocks. Today adjustable rear sights, both open and optical, and good mounting systems are available for shotguns. With these, it is as simple to correct a turkey gun that's shooting "off" as to sight in a rifle.
With a well-sighted gobbler gun, you are ready to take on turkeys at all reasonable ranges rather than be put at a disadvantage by tight patterns at close range.

It's not too soon to start practicing with your turkey calls for the upcoming season. You don't have to be an absolute master of the call to be a successful turkey hunter, but being competent sure doesn't hurt your chances for success.
Start out with your old favorite calls to get back in the groove. You might want to replace some of your diaphragm or tube calls because latex deteriorates with age. Better to break in a new call early on than have last season's favorite go sour on you in mid-season. Also by starting early you can experiment with new calls (both makes and call types) and maybe find something that works better for you.
With all the excellent video and audio tapes available, good turkey call instruction is widely available and learning effective techniques is not the slow curve it once was. Visiting local turkey calling contests is also a good idea. Hearing top-ranked competition callers and attending their seminars might help your technique.

Shotgunners prefer to shoot for the gobbler's head and neck. For even very good archers this is a very difficult target. A gobbler's head is a small target and is seldom still for very long.
Bowhunters should focus on the heart/lung vital area. The best way to do this is to imagine that the gobbler is wearing a cape, fastened around the base of the neck, that drapes down over the upper 1/3 or a bit more of the body. That about covers the vital area.
The only weak spot in the gobbler's "body armor" is the upper back. This area exposes the spine and covers the heart/lung area with little muscle or bone. From the side, the "wing butts" of the upper wing, which contain heavy feathers and strong wing bones, cover the vitals. From the front, three inches or so of breast muscle cover the vitals. For these reasons, powerful hunting bows are recommended for gobblers, particularly if you are using mechanical, expanding heads.