I suppose there are also hybrid ways to do it, and you'd probably use different ways for different circumstances, but when sitting down, for yourself, to calculate your net worth, what is the PROPER method?

With the right skinny contract and the perfect controlling clauses and contingencies you can do deals all day without lots of money or need to setlle.It took me years to discover this technique, but now that I understand the Control and Roll method of making money by selling real estate I don't own, I love it and profit from it all the time.

So what I'm curious about is the best method to obtain this cash for the down payment.

The property still had to appraise.Now, down payment assistance cannot have funds derived from the sale, so this kick back method is not legal from a federal perspective.As to the question of having other assets encumbered, yes, that is done. 

Frustration leads me to reading: 4 Hr Workweek, GTD Method, J Scotts books on flipping and estimating and FLIP and HOLD and the One Thing.What's my big hairy audacious goal for 2016? 

I'm looking to buy and hold, to use the BRRR method.  

I think it's a great strategy and will really start targeting corporations in the method @Kevin Harrison mentioned (which is awesome by the way.

@Andrew MeyerBoth methods work out to about exactly the same for me.

You should also be aware that there are two methods to use your 401K money in real estate investing.

Investors could have different methods to accomplish the same goal.