Always let the first bird of the day work untill its clear the bird is gonna leave NOW, or its landed. Odds are unless theres a significant wind/weather change, thats what the next birds will do. If bird no. 1 lands short, open up more space for em and double check the camo. You can have the best spot in the world, but if the birds aren't comfortable at landing in your spread, they're not gonna finish em. Also experiment with calling styles early to see what they want on that particular day.
Tip #2, if you're in a slump, take target practice on low pressure targets like coots, mergies, hens and other nongame but legal to shoot birds like starlings, pidgeons and the like (be sure of your target, your state's regs and use the meat). Focus on your form and only allow yourself one shot. I find having a target where there is no pressure really helps you get back to the basics and focus on what you are doing. I mean is anyone here sad they missed a shot at a coot? I always do this when I'm hunting a spot that has no shell restrictions.
Which brings me to #3, to clean a coot place it back down, grab its legs and pull, a quick way to get a lot of meat
Some mistakes are too fun to make only once