I was "soloed" in less than an hour with a 2 channel, 6 foot span glider. The instructor trimmed the plane for a gentle rate of decent when you let go of the stick and told me to move the stick to the low wing to level it out when flying it towards me.
This is the most "intuitive" way to learn and I've passed the same method on to my sisters and a few friends.
I skipped the typical 4 channel trainer ....an "Ugly Stick" was my 4 channel trainer. A 3D Profile with the controls dialed down would have worked just as well. They will land in 1/2 the space that the typical 4 channel trainers need.