If you don't feel like playing with proportions, Demitri's Bloody Mary Mix works like a charm. He's a local guy and a friend of the bar where I work. We use his mixes (he has several kinds) and couldn't be happier with them. I know people may poo-poo the use of a mix in these times of artisan cocktails, but Demitri worked as a bartender for 20+ years and the formula for his mixes came from years and years of tinkering with ingredients. You can pick some up at Cash & Carry and several grocery stores. I like the Chipotle-Habanero, but the Original and Chilies & Peppers varieties are probably easier for most people to handle. I like to garnish with Arbequina olives (which add a nice amount of bitterness and complexity), pickled asparagus, pickled green beans, a wedge of lemon, and a bacon salt-celery salt rim. But my favorite bloody, from Palisade, comes equipped with a giant prawn. That would be a lovely garnish for Christmas morning. Jarred, smoked oysters, such as Hama Hamas, would also be nice.

https://www.demitris.com/home
For Arbequinas, etc.: http://www.delaurenti.com/index.html
http://www.hamahamaoysters.com/

If you're dead-set on making your own, here's a good recipe:
* 2 ounces vodka
* 4 ounces tomato juice
* 1/2 teaspoon freshly grated horseradish
* 2 to 3 dashes of Worcestershire sauce
* 3 dashes of Tabasco Sauce
* Pinch of coarse salt or sea salt
* Pinch of freshly ground pepper
* 1/4 ounce fresh lemon juice
* Pinch of celery salt or seeds, crushed
* Wedges of lemon and lime
http://www.chow.com/recipes/10034-bloody-mary