Emily Rain, one of the problems with mulling wine is that the heating of the red wine accentuates the tannin in the wine, (thats the stuff that makes your teeth feel furry), the way to offset this is to add sugar(or the sweetner of your choice) and spices and use a microwave to warm as mentioned, this reduces the "cooking time". If you are in the UK a reasonable Bulgarian Cabernet Sauvignon would do and about 2 ounces of spirit of choice, zest of orange or lemon and, cinnamon and ground cloves and spices of choice, go easy on the nutmeg as too much is hallucinogenic and Myristica poisoning is distinctly unpleasant, being drunk or worse, hung over with Hallucinations, no thanks. Ideally your local Health food shop will do sort of mulling "Bouquet Garni" and dark beer and cider can mull really well, too. Go for the sweeter end of the range tho' Guiness mulled is HORRIBLE.