If staging the trigger works for you, do it; fact is, though, it doesn't work for everybody. I was frustrated with DA shooting for years until I chanced to meet at the range a retired law officer who had been a competitive shooter for several decades. He watched me shoot for a while, then offered to coach me a bit. His first comment, "Stop staging the trigger!"
Instead, he counseled a smooth, continuous, straight-through stroke while concentrating on keeping the front sight where I wanted the bullet to go. It seemed too simple, and too good, to be true, but he knew whereof he spoke. Within just a few rounds my DA shooting had improved exponentially, and from that day to this if I can hit a target SA I can hit it DA.
This method teaches you an important fact -- a smooth action contributes far more to accurate shooting than a light trigger pull. Much better to spend your time/money on smoothing an action than on lighter springs.