For me the best thing to do is start the climb a bit slower and let my legs and body find the rythem it wants to ride at. Onve there its just cruising on up to the top. I spin a high cadence most of the time, but on climbs I prefer 80 down to 70. Its all cardio really, the high cadence while climbing gets me cardio wise. So push hard, back off, push hard. As your body learns to recover faster you should be able to find that sweet spot.