Correctly fitting any harness is extremely important. While each make and model will have specific fit characteristics and instructions, there are several areas to note when fitting any harness.
Always open all of the harness’s clips that you can. This may seem obvious but many well-designed harnesses open so it does not have to be put over the dog’s head. When you are working with an “easy going” dog, especially one you know well, it is tempting to keep the head piece attached so that you just slide it over the dog’s head, instead of undoing it and snapping it around the neck. While this may be totally fine, some dogs will eventually become head shy from sliding the harness over their head and ears.
Any harness should lay flat against the dog’s body. If you are using a harness that has a connector strap between the front legs you will want to check that this strap is flush against the sternum but not so short that it is pulling the barrel strap into the elbows.
When checking for fit, be sure and notice how tight or loose it is when your dog is standing, sitting, and lying down. Your dog’s movement should not be inhibited at all, and it is worth paying special attention to how the harness fits in relation to your dog’s shoulders and elbows.
After removing a harness, it is a good idea to reattach all of the clips so it does not become tangled in storage.