First thing first, if you shall have a fire place (or a stove), it must be here. Have bellows and a poker that goes with it.
The fire place mantel is the good place to put lace doily, porcelain figures, teapots, cups, coffer grinders, vases, candlesticks, oil lamps, and so on.
The furniture will depend on which style the living have. If it’s rustic, a slice of tree can be used as a stool, and decorate with pinecones.
If it’s elegant, think by English style Victorian chairs, wall paper, carpets and table. It look better with velvet curtains.
Unless your library is a dedicated room, put a bookcase here (the older the books, the better).
If you have a TV (and/or the internet box), put it in a closet. You can try a shabby chic style instead. Fabric is mostly flowery, on chairs, sofa, carpets, and curtains.
Said curtains can be gathered, by a strings system that allow them to look pleated to let the sun in. But it also look pretty.
Every obsolete object that is not in the kitchen can be exposed here. Like bed warmers, churn, fire heated irons, coal buckets, fans…
A grandma clock is a must have. Also furniture with a cozy look. Like ottomans, or footstools.
Favor velvet, flowered or patchwork fabric depending on your style.
A chandelier can be used for a light ceiling. An English traditional aspect will look very cozy, the more carpets, heavy curtains, cushions, plaids on chairs, the better.
Pictures can be authentic, but also reproductions of classical pictures, water colors paintings, engravings…and framed, once again. Really, heavy metal or action movies posters will not blend well here…
Plants and flowers will be a nice touch. We may not have fresh flowers to put in a vase every day, but think by fabric and dried flowers.
The dining room can be the same room, but if not, it can be the same kind of setting. Have a large wooden table and chairs, and a dresser to expose your finest china.