My advice? Don't tie the proposal in to any other occassion. She'll want to be able to enjoy it, and piggybacking it with some other event (like a birthday) could make her feel like you were "killing two birds with one stone", so to speak.

More advice? Make your proposal a good one. Be romantic. Definitely drop to one knee. Her friends will all want to hear the story in excrutiating detail, so give her something good to go to them with. Mine was spontaneous, but very, very lame and has been fodder for good-natured kidding for the past 12 years. Well, mostly good-natured.

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Jonathan

2011 Mazda2
2000 E320 4Matic Wagon
1994 C280 (retired)