Start with good bike fit. Is the saddle at the correct height, such that your hips don’t rock? A ballpark check is while holding yourself against a wall while on your bike, put your heels on the pedals and pedal backward. You want to just lose contact at the bottom of the pedal stroke without dropping your hips. Is the saddle setback correct? With crankarms at 3 o’clock and 9 o’clock, a plumb line from the front of your front knee should intersect your pedal spindle. These are ballparks for a road position. Each individual may vary and there are other disciplines such as time trial and triathlon that would have a different position. A professional bike fit is really the best place to start.
It is considered optimum to have a cadence of 90-95rpm over the course of a ride. For hills, this will drop, but it is important to limit the amount with correct gearing. Most bikes come with a 39-tooth as the smallest ring up front and a 23-tooth as the biggest on the back. This may be suitable for you, but if you try these gears on your chosen hill and your cadence is below 50, it’s time to consider alternatives. For some, changing to a cassette with a 25 or 27 will do the trick. You could also opt for a compact crankset, which will have a 34 as the smallest ring. You may even do both. There are also road triple cranksets available to give even easier gears. It’s best to try training on hills first since there is some expense to making these changes.
This is the part that most people get wrong. It seems in our nature to want to conquer hills as aggressively as possible. The quickest way up over the long haul is to go slow and steady. For hill repeats, I’d suggest going very slowly for the first repeat. Feel as if you could carry on a conversation. Let subsequent repeats feel only slightly harder each time. Learning to climb easily will make hills not seem so bad. As you get stronger, you can add harder repeats to the mix. I like climbing alone. Having others with me can make pacing difficult since there is a tendency to try to keep up with that person in front. Ride at YOUR pace. For longer climbs, the pace should also start out easy. Let it feel almost too easy. Then it’s all about rhythm. If you climb at the correct pace, your breathing and pedal strokes will become rhythmic and the long hill won’t feel so insurmountable.