The hammer and setter and tips and mat are used for setting eyelets - there are lots of Youtube videos showing how that's done. The craft knife is for cutting small things, or the insides of shapes, or things with tricky shapes at the edges. The tweezers are for placing small items. The emery board is for giving the edges and surfaces of paper a distressed look. The piercer is for making tiny holes for brads or stitching, and the round end of it can be used for applying rub-ons or doing dry embossing.