Flex, a SCL is important as you mentioned but not always NECESSARY if your looking to cut trees... Just gotta stay under 5 bills a day and work solo.
I don't think there is any special formula or technique to discover, although you can learn a lot from others and I see where your coming from.
I'm training someone currently and I feel like 'training' is an overstatement. My idea of teaching or training someone is to set them up with the gear, tell them how I would do it and leave the rest up to them.
For me, training is an investment of time and money. He's 26; no kids, clean, smart, great attitude, and most importantly is a fantastic human being... HARD TO FIND. He seems to be a natural, with a real hunger to learn... So we'll see how it goes.