Okay. you got it. Everyone recommends a cadence sensor.
Then what?
Well, then you need to use it.
The way I learned to raise my cadence was just to ride known routes and my regular distances for a week to determine what my existing cadence was. After that, a few days where I rode portions of my normal rides at a slightly higher cadence - 7-12 rpm higher - tuckered me out. Aka intervals but not INTERVALS, you know what I mean? Then, I lengthened the portions ridden at the higher cadence, took a week off to just ride without the cadence sensor and then repeated the entire sequence.
After about two months, I was ~17 rpm higher in the same gear(s) over a 50 mile flat "course" (we don't have hills where I live).
Try it. YMMV.