I'm eternally grateful I have never met an UP child. It would not end well.
I shout, smack occasionally, hug a lot, EBF, co sleep sometimes, send DD2 to her room until she wants to be nice and have never own a parent facing pushchair.
I use rewards occasionally and praise if deserved and lots and lots of reasoning and explaining.
I call it the only muddling along with what seems to work school of parenting.
And you know what it seems to work, DD1 is the nicest teenager your ever likely to meet and DD2 gets school reports which glow in the dark.
They are both feisty, opinionated and as different as chalk and cheese.
And at 15 and 12 we rub along without me ever having to remove privileges, dock pocket money or cancel things and thus avoid a whole lot of resentment and angst.