As a one-handed rider, I can't generate any power standing, so I'm a sit down guy on climbs. A few things have helped me.

On shorter climbs, I tend to start slow in a lower gear, high cadence, and ramp up until I'm hitting the top going faster than the bottom. On some frequent local climbs, as the season progresses, the gear I start in is higher, and the upshift points come sooner.

On longer climbs, changing my hand position at relatively consistent intervals, from drops to hood to top, both saves me butt pain and improves my overall power. For example, I'll spin 15 minutes in the drops, until I'm starting to feel it in my lungs, and then sit up and ride with my hand on top at a lower cadence. My lungs recover, my legs start to burn, and I move to the hood for a bit. Rinse and repeat. Focusing on where I am on the bike breaks up the climb a bit better for me than waiting for mile markers.

Then again, I'm not racing, just trying to get to the top in one piece.