Years ago, Connie Carpenter and Davis Phinney, former Olympians, taught me this trick.  It’s called the miracle shift.  The objective is to power over the climb using bigger gears than you would normally use.  Let’s use a climb that is at least one mile and it’s steep, but not so steep “oh my gosh- I can’t get up that!”  So, at the base of the climb you roll into it using a small gear and your are spinning fast!  You continue spinning until you are bouncing in the saddle, shift down 2 gears, stand up and power up for 20 seconds, then sit down and shift back one.  Then repeat step one by spinning until you are bouncing in the saddle, shift down 2 gears and power up for 20 seconds, then sit down and shift back one.  Eventually, you will be at a place where you are building strength while climbing and you will have also improved your spinning ability on the hill.  I use this trick quite frequently when climbing especially on the longer climbs!