One thing you will want to do is sweep her off her feet..... touch her heart with warmth and make it memorable. Every girl is different, just like every guy.... and the combination of the two together brings yet another dimension to the whole scene making each couple unique as well.
Step one - Sweep her off her feet..... you might try simply having fun getting her to stand on her head. (stand on head = swept off feet)
Step Two - touch her heart with warmth..... while she is standing on her head reach down and squeeze her left breast (that is as close to touching her heart as you can get) ... make sure your hand is warm as you want to touch her heart with warmth remember.
Step Three - help her stand up and get down on your knees as if you are now going to stand on your head.... but first say "I better empty my pockets" .... reach in your pocket pull out the ring and say "I love you in ever way.... even upside down you make me feel like I am more than I am..... will you marry me"
you may choose alternate activities for step one and 2..... but step 3 fits almost any other occasion... just make sure the occasion will be as memorable as standing on your head......... (what girl would ever forget you asked her to marry her after she stood on her head.... now that WOULD be memorable LOL)
I wish you and your lady the best of everything for as long as you both shall live.
Love - Light - Laughter