My system, for what it's worth:
Christmas Eve: go play a round of golf with the homies. The ones with the Cuban cigars.
Do four shots of tequila at your local watering hole. A good local bar will put a worm in each shot. Drink Cuervo Especial, not that gourmet sippin' shit. You buy that stuff to get girls drunk.
Go to Victoria's Secret. Spend 50% more than you both agreed is "the limit" this year.
Buy everything a size too small, except for the bras. Buy those a size too large.
On Christmas Day ask her to model her new step-ins and sech for you. She will look at the size tags and demur.
Say 'I understand. You might want to exchange them for a different color. Here are the receipts.'
Get your annual pity fuck. Go on, take it. You earned it.