I choose collars based on their style or function. However, more often than not, I am most interested in a collar's function as it relates to a given task. Here are some of the collars I use, along with information on when I use them. An eCollar can be paired with any of the collars listed below. When the eCollar is used in conjunction with another collar, the eCollar is used for pressure on / pressure off and the leash attached to the other collar provides directional guidance.
Flat-buckle Collar
The only purpose I have for a flat-buckle collar is to hold dog tags. The flat-buckle collar does not provide me with a meaningful way to communicate with the dog wearing it. I choose flat-buckle collars based on their material and aesthetics because I do not connect a leash to them.
Martingale Collar
The martingale collar is my collar of choice for most dogs. The collar is designed to tighten when tension is applied to its D-ring, so it is nearly impossible for a dog to slip out of it. Additionally, I like that it provides a very generic pressure on / pressure off sensation for the dogs that is perfect when I have the dogs dragging a long-line behind them during off-leash training exercises.
Prong Collar
A prong collar is not magic, but it is really close to it. The prong collar provides a simple way to communicate with our dogs, i.e., pressure on / pressure off. The prongs on a prong collar provide a bite-like sensation to dogs' necks that makes them more effective than a collar like the martingale that does not have them. Dogs respond quickly to the sensation of the prong collar, so it very easy for us to teach them what we want them to do. The prong collar is my go-to for teaching dogs positioning for the Heel command.