Hi Ed,
try to avoid pewter with a lead content as the fumes are not good for you. I melt it down in a saucepan on my camping stove in the garden. I cast it into round ingots, I drilled 2" holes in dry plywood for casting my ingots into.Whatever you cast into ensure there is no moisture present or it will spit out, I wear a protective mask and welders gauntlets. Cast into a mould and when cooled apply CA glue to hold it whilst turning. I find that it turns easier than wood as there is no grain direction to worry about. I would scrape to begin with but as you progress you will find that you can turn it rather well with gouges etc. but I advise getting "a feel for it" first.
Clean up before you start turning it as you can save the shavings to reuse.Be careful though when sanding as it will warm quite quickly which could lead to damage of your workpiece but also the pewter oversand(??) can stain your work , to avoid this I sometimes cast, turn, finish and then fix it onto my work, depends on what I am making.
Hope this helps.