I would take projects that I work on and the thread that I use. I would check around and see what options I wanted compared to what is offered. Do you want an automatic needle threader? Do you want a thread cutter? Do you want electronic or computerized machine? Do you want a large harp, if so how wide do you want? Do you want an oscillating bobbin or a top loading one? Have a general idea of what you want in a machine as well as a price limit. If a business isn't going to let your try a machine, don't buy from them. You wouldn't buy a car without trying it out, would you? Sometimes the dealer will take 10 layers of denim and demonstrate that it will sew through those 10 layers. Are you going to be sewing through 10 layers of denim? If you are, great machine, if not it is just a dog and pony show. Take cotton layered with some batting to sew, too. Good Luck.