I have collected, processed and sold some 700 pounds of pewter and I have tried many methods to process it. Cutting it with saws, clippers, etc. are time consuming and difficult. The best tools are a sturdy bench vise and a 3 pound drilling hammer. For teapots and the like, clamp the legs, handles and spouts in the vise and twist them off. Use the hammer to crush the body into a rough tube small enough for your pot and feed it in as it melts. Trays and plates, clamp a few inches into the vise and fold it over. Hammer the fold flat and repeat until you have a tube and feed it to the pot. Bowls, fold the edges in and hammer as required to fit the pot again.
Pewter is relatively clean compared to scrap lead, but there is dust from sitting, sometimes varnish has been applied to avoid tarnishing and of course the oxides from melting. I melt at 500 -550 degrees. The alloy will melt at lower temperature, but I have found the sawdust I use to reduce the oxides back in work much better at 500 plus degrees. Molds are all preference. I use Potter molds. The 2 small cavities of a Lee ingot mold are about the right size. Decoy weight molds are good. Some use large bullet molds. At least one member here uses the bottom of beverage cans to cast coins. If you use anything other than a bullet mold, cast the ingots thin enough that you can snap them for smaller additions to the pot.
I strongly recommend you read the first few pages of the Hallmarks thread linked in my signature. Good luck.
http://imashooter2.com/pictures/pew6s.jpg