Depending on ability I guess.

The gung ho way would be to stand and power your way to the top maybe sitting down when you've put distance between you and the person you want to drop.

Ofcourse this could backfire if they are stronger than you or if you blow up and they eventually just catch/pass you with their steady and yet not so tiring pace.

I personally like coming from behind, and spinning as much as I can, match them at around the middle of the hill and see if they can keep the increasing pace. Worse case scenario I still have a little something for the final mashing at the end (assuming ofcourse one of us is still around).

I do believe though that there is a big psychological boost if you can put distance as early as possible.