I am no expert but I would assume start with small flights from a perch to your hand and back to the perch. Although that would mean training it commands
Then you could slowly increase the distance, then start adding heights/descents, round corners?
I would do all this inside, I would never take a bird outside unless it is harnessed.
I believe Michael got Kili clipped, although she was younger, but I suppose they are never too old to learn!
My sennie who is 12 weeks old is not clipped but hasnt perfected landing, although I think the issue is mostly because he wants to land on my head! I raise my hand and sometimes he will sort of hover for a bit then land on my hand... But other times I think it startles him and he continues flying over me and usually then crashes (softly) into something behind me..