I am not a professional cabinet installer.  I have done a few installations for remodeling jobs in my home and the homes of friends.  I am also an avid amateur woodworker.  For that reason I own a ton of different types of clamps.  In the past I always used either "F" style or wooden hand-screws to hold the cabinets together for joining.  This past winter my wife and I turned our bonus room into an art studio for her.  The remodeling called for the installation of several cabinets along 2 walls.  Since I would largely be working by myself I decided to invest in a pair of Pony Cabinet Claws.  Wow, these things are game changers.  I strongly recommend them.