Marrage, poems, and friends

So I've been requested by a friend to write a poem to ask his girlfriend to marry him. I have no idea where to start, some suggestions, like length, or what I should involve, would be appreciated

No offense but don't you think that your friend should be the one to write it? If he is asking someone else to write it for him, to me that makes me think he is not serious about proposing at all! I don't think bad of you, but your friend should feel very bad, if he truly loves the girl then he would sit himself down and write how he feels about her and how he can't see himself without her in his life, and how finding her has made him a better man, that is the stuff he SHOULD be writing himself! and if he can't do that much tell him to go to a card store and find a romance card and just use what it say instead! It was nice of you to try and help but tell your buddy to man up if he wants to propose to his girl! Good Luck!

Diddo!

thanks, aha well we'll see how he fairs out. trust me I've seen his poetry and it took him like a month to write a poem that was half decent. so I highly doubt he is gonna be doing that. he wanted me to do it because through out school so far I'm known as a good poet aparently, I started to stop bad habits like cutting, and ever since I've written once in a while, when I feel the need or when im simply just bored, and he really wanted a good poem that'd make her cry with tears of joy, if he writes it she might cry, but not from the poem xD
Thank You All, Really Appreciated,
D