Ideally?

We would be on a camping trip to our favorite spot and just under a waterfall or at the peak of the area I would take a breather, slowly walk behind her and wrap my arms around her waist and turn her slowly. Look her in the eyes and say some line that relates to her being more gorgeous than the view and just like the mountain/waterfall being there, I would want to be with her for all time. Then kneel and ask her the question.