Sorry man. Didn't mean to throw you off. You got the right idea on how to learn modes. For most people making the transition from the major scale to learning the modes, your way is the simpliest. The only hold back I think it has is, by knowing the major scale already. You pretty much got the sound of a G major scale in your head. By going right to the A dorian, it's harder to grasp the uniqueness of the mode itself. It's the same notes, G major and A dorian. So although you may learn where they are on the fretboard, the sound is confused. Your ear still says the A dorian sounds like the G major.

The way I proposed builds both ear training of each mode, and how to play their pattern on the guitar. Without having to resort to the G major first. Which doubles the work. My explanation is not how to use them in a song, but how to learn them seperately. Going from C Ionian to C dorian to C mixolydian etc. etc. gradually builds on the uniqueness of each mode itself by altered one note at a time. Then listening closely to the altered note. Read that post again, I think you'll see what I was saying. This was how Bach was taught modes. In the end you are learning the pattern and the sound of each mode. Knowing the sound is the most important element to be a musician. A musician is a master of sound, not a master of patterns.

Hope this helps man.