I love putting and I'm generally considered to be a good putter, so a few things that might help:
At the level you are trying to play, shooting 80, a median miss should be about 10% of distance (a tour pro is 5%). So from 40 feet you should be within 4 feet at least half the time, from 20 feet you should be within two half the time. So, and I'm making this up a little bit, if you are regularly more than 6-8 feet from 40 feet or more than 4 feet from 20 feet, you should work on your lag putting.
As someone else said, make sure you're realistic. I spent a winter practicing 30 foot putts in my basement. I got better at them. I make more, but not enough to ever notice in my score.
I spent another winter hitting, and I do not exaggerate, thousands of 7 foot putts (that's the amount of carpet I had to work with). My make putting got better and I could see it in my scores.
For me I think of an 8 footer (3 steps) as a make putt, maybe extend to 10-15 feet for an easy uphill putt and shorten to 5 feet on fast downhill putts. Everything else is a lag where it's a bonus if it goes in.