"What kind of methods or tools have you found useful?"
First, our chickens are VERY free ranging. This ends up impacting what the meat is like as well as how to immobilize them. As noted elsewhere, it's rare to be able to catch one as they are fit, wily, and tend to stay out of your path. For the most part, we need fewer roosters, so one obvious way is to wait until 2 are fighting and just club one or both of them in the head. Otherwise from longer range, a .22 or .177 rifle or pellet gun is used to drop them and then they are immediately decapitated or whacked on the head to knock them out.
After decapitation, they are hung to bleed out. We've found this can be done over several days with no negative effect on the meat; less of a concern in the winter, but also in the summer if you hang them in a cool root cellar.
I've tried both plucking and skinning. Don't know if it somehow is due to the "toughness" from free-ranging, but I find skinning them rather difficult...have used several YouTube videos as a guide, but certain parts on the back and elsewhere just don't want to "peel" very easily. (Yet my dad always just skinned ringneck pheasant's after hunting, so I can't say being more wild contributes to this difficulty.) We rarely pluck/process more than 3 birds at a time. Plucking is pretty easy: Use a big Tupperware tub in one sink and fill the other sink to about half-way with cold water. While water is boiling, clip off the wings, but leave on the feet. Technically the water should be scalding, but it's often boiling when I pour it over 1 - 3 birds laying in the Tupperware. Using their feet as handles, slosh them around in the hot water for several minutes, then pour the hot water into the other sink 1/2 full with the cold water. Start with one bird, drop it into the cool water, then rest it on the edge of the sink and start plucking...a rubbing and plucking action starting from the legs and moving towards the neck. The sink with the now warm water is a great way to remove the feathers from your fingers...the feathers will collect in the water and, when done, just scoop the wet feathers into a discard/compost bin and when the sink drains, collect the residual feathers in the drain strainer. (Without this latter addition, we had feathers all over the kitchen.) Some parts will be more difficult than others...around the wings and tail, I just trim with a knife or poultry scissors. Second to the last step is cutting off the tail with a knife, then finally breaking the legs at the main joint and cutting through the sinews to release the feet.
Now the best part....hand them over to my wife for the evisceration!

My excuse is that my hands are too big, but actually she'd rather do this part than the plucking or skinning, so it works out. In any event, she uses a poultry scissors to open the cavity and remove the innards, cooking the liver and other parts either for herself or the dogs. Do just a few birds at a time, and before you know it, your chest freezer is pretty full.