Along with this, the thing that helped me the most was learning to run much slower. I would always run at an uncomfortable pace that would jack my heart rate up and have me huffing and puffing. Then I learned about "Zone 2" training which essentially boils down to running at a pace where you could comfortably have a conversation and more easily run for extended periods. This now only made it so I could run more miles per week, but it turned running from an exhausted effort to a more meditative, enjoyable one.
Things I think have helped me the most:
1. Correctly fitting shoes (I always wore shoes that were too narrow and short for my feet)
2. Wearing a heart rate monitor so that I could run at a pace that allows me to stay within the heart rate range that improves aerobic fitness while being easy enough to sustain (heart rate zone 2)
3. Increasing my cadence to the 170-180 steps per minute range, which has allowed me to improve my form/efficiency and avoid shin splints.
Things I think have helped me the most: 1. Correctly fitting shoes (I always wore shoes that were too narrow and short for my feet) 2. Wearing a heart rate monitor so that I could run at a pace that allows me to stay within the heart rate range that improves aerobic fitness while being easy enough to sustain (heart rate zone 2) 3. Increasing my cadence to the 170-180 steps per minute range, which has allowed me to improve my form/efficiency and avoid shin splints.