I've tried wearing our local mountain down, but that hasn't worked... yet (I'm stubborn and still trying). It's still as long and steep as ever; however, crossing over it and back isn't as daunting a task as it once was. The first time I tried the whole mountain, I bonked on the way back over, sat under a shade tree on two different occasions, and finally made it back to the vehicle.

I have, however, done a lot of what has been recommended here, and those things do work.

I know this is blatant heresy in these parts, but I have a triple chain ring and a 12-27 cassette. I set a steady, sustainable pace/cadence and breathing pattern (for me) and do my best to stay with it. For most of the climb over and back, I don't use my lowest two cogs any more. I make sure I'm well fueled and hydrated along the way.

Stay with it!