I watched The Drone Coach series of FREE YouTube videos. After watching it through once I planned to watch a couple others, but the other two I tried both had errors within the first couple hours of watching (when it differed from drone coach I searched official FAA study guide to see who was right) so I just went back and watched the airspace and sectional chart portions of the free Drone Coach YouTube series two more times, at which point I felt very confident.
I took the test last week and got a 95%, which I completely attribute to the free drone coach videos and nothing else. I was in and out in less than an hour
Again, I spent $0, I took 0 practice tests, and purchased or reviewed 0 question/answer banks, just what was embedded within the drone coach series, easy 95% less than a week ago. Couldn't be happier
Edit: But I definitely had to watch airspace and sectional charts at least twice to feel okay and ended up watching them three times to really absorb EVERYTHING
I didn't even have to check the legend