Honestly, one of the best ways to learn the most efficient way(s) of botting is trial and error. I started really getting into goldfarming in 2013, I did what I saw a lot of people doing and that was spinning/picking flax, after a while I searched for better methods. From my experiences in 2013, I enjoyed money making with combat involved. I liked earning gold while also leveling my combat skills to be used for something more useful, so I searched around and saw that a new script at the time for Chaos Druids was popular. I bought it, trained a few accounts to the recommended stats and let them go at it, I was making some great money.
I eventually moved on from that and put those accounts up for sale since they had high level stats, and found some great ways to make money.
It's all about trying things out. I quit after 6 months of botting in 2013 due to school, but now I'm back. Most of the methods I use to do I never tried again, but I have found what works and I go by that.
I hope some of this helped