I have a three-step process.

1.) Make sure the occasion truly is special.

2.) Call MR and ask them to put a note on my reservation

3.) Bring aforementioned notation to the attention of the front desk during check-in....if not a day or so before.

My success rate for upgrades and/or some other sort of gift/perk/acknowledgement with this approach is at or near 100%. Marriott people are out to please...espeically their best customers. Always be polite and explain clearly why you are making your request. Respectfully ask the hotel do do you a favor that consider very important.... and don't play the DYKIA card. Odds are the hotel has heard that latter one enough times to be to be completely sick of it.