How do I confit a Pork Neck
Your question is bordering on being too broad, there's no "best", or at least everyone's "best" will be different. Here's what I mean:

method 1: Says to bone the meat but keep it whole, brine it overnight, and then confit it in rapeseed oil (canola oil)
method 2: This one says to cut up the meat beforehand, dry rub it with spices and salt overnight, and then confit it in rendered lard

These two recipes differ in many points but both are valid. Cut it up or leave it whole - either. What fat to use - whatever you like. What temperature - varies. The only things where these two methods agree are: 


Brine, marinade, or dry rub the pork overnight to improve flavor, tenderness, and juiciness
Confit for about 4 hours 
No browning before starting the confit. I've never seen a confit method that says to brown before, some say brown after
Both call for removing the pork from the oil, cooling, wrapping it in plastic wrap, and then refrigerating it before re-heating it at a later point


So how to do the confit depends on the effect you want. If you want something to be easily and quickly served then cut it up before hand, you'll also use less fat overall. If you want something impressive to put on the table leave it whole with the bone in, then pull it apart with a fork. If you want a really rich confit then use lard, if you want it slightly less rich use a lighter oil. Usually you confit using the same fat as the meat or poultry, however in this case I'd personally go for a lighter oil rather than lard, but that's purely my opinion.