I'm a "newbie", so I read a bit and decided to first go the "blow out" route. BUT ..... It seemed that no matter how long I "blew" the lines, or how long I waited to repeat the process, the additional "blow" always resulted in more water.
So, I went for the "pink" route. While evaluating which kit to buy at the local Camping World, another camper was doing the same thing. Seems he only "blew" the lines last year and found some small cracked connectors at the low-points of his system. Even the tiniest amounts settled to create enough volume to create a "freeze point".
The other issue, and one I also ran into, was the placement of the system's water pump is such that introducing a by-pass valve, to allow for "pink" induction, was nearly impossible. I ended up directly connecting the tubing attaching to the pump and filled the lines that way.
You would think that manufacturers would spend the extra $2-3.00 and put a by-pass in the system as a matter of courtesy.
But, then again, after only having the RV for one season, we've found PLENTY of shortcuts they took, some cosmetic and some structural, that haven't made much sense.