Clickers are good training tools for dogs because they produce a distinct sound (it won't get confused with other similar sounds) and allow you to perfect your timing. (canismajor.com)
A current plan can also be a good training tool. (entrepreneur.com)
And all my hard - earned wisdom and experience has led me to conclude that, for me and my clients, the best training tool and approach for strength and conditioning — hands down — is kettlebell training. (giryastrength.com)