I'm one of the people Mikey4444 is telling you to ignore, in that I have never found any discernible difference in the end results between parboiling in salted or unsalted water so I always go with unsalted. I largely agree with everything else that's been said. One slight difference is that once drained after parboiling, I leave them in a colander over the empty pan to steam-dry, then put them back in the pan to shake them and rough up the outsides. I then tend to leave them to cool completely, so the parboiling stage I usually do quite a bit earlier than everything else.
I don't add any flour, and most of the time use veg oil, but find that goose fat gives the best results. When pre-heating the fat/oil, I might leave rosemary, thyme and whole unpeeled garlic cloves in the tray to give some flavour, then remove them before adding the spuds.
All the above has unfailingly yielded excellent results; crisp and nicely browned on the outside, fluffy and moist on the inside, and bearing mind your comment at the top, better than what I've generally had in restaurants.