Installing the baseboards first makes it much easier to dye and paint the baseboards, since you don't have to worry about staining or painting the new carpet. Use a spacer if necessary. Something that is much more difficult to judge when the carpet and the base layer are inside. When installing the plinth before the carpet, the easiest thing is to install it even with the lower edge of the drywall, as described above.
In some cases, this will not be possible, since not all drywall is spaced above the floor in residential construction, although ideally it should be. In these cases, it is best to follow the carpet manufacturer's recommendations for mounting the motherboard. Most of them recommend 1 inch to make room for both the pad and the rug. It is also better, if possible, to fix any adhesive strip with nails before installing the socket to prevent damage to the socket from errant blows of a hammer.
Nail the socket into place with 2-inch finishing nails and a hammer, or with a pneumatic nailer. If you are going to install a base shoe or a quarter of a round, attach it only to the socket, never to the floor. Contractors usually choose to install the motherboard first. That said, both installation orders have advantages.
If you install the carpet first, it's very easy to place the plinth over the top edge of the rug. However, installing the baseboard first allows you to dye, paint, and seal the baseboard without fear of leaving permanent marks on the carpet. Having a finished carpenter do all this type of work on a block is a more economical use of time and personnel than waiting for the carpet to have been installed. First of all, if you already have a carpet installed and you're updating or redoing your baseboard, there's no need to tear off the carpet.
The only thing I can say is that if I do the work of installing the baseboards and the moldings myself, I will first make the baseboards and then place the carpet underneath. However, if you're redoing or installing both the carpet and the baseboard, you'll have to choose which one to install first. If the adhesive strip or carpet is not aligned in the areas where the socket is installed, it may be difficult to install it level. Everything Malcolm said, besides that the painter can always come back to do small touches in case the carpet installer causes minor damage (hopefully) to the molding or drywall.
The steps described here include cutting the carpet and using the appropriate tools and techniques to place the carpet against the wall. The main advantage of installing the baseboard first is that it allows you to paint, stain and seal the baseboard without worrying about damaging the carpet. I'm looking for feedback on whether there is a standard order in which the baseboards and rugs are installed. However, it should be easy to retouch, and retouching it is easier than trying to install and finish the molding with the carpet in place.