How would you place furniture for living / dinning room combo?

place your dinning room furniture closest to the kitchen. make two seperate spaces out of one room by dividing them with a screen or have the back of the couch face the dinning room maybe even put a small table or armor against back of the couch.

set up a seating area in one section, probably further away from the kitchen and put an accent table the same length of the couch at the back of it. then put the dining room on the other side of the accent table.

OR

take a folding screen/separation screen and put against the wall between the two areas. of course not coming out all the way across the room, you'd leave a space for entering and exiting.

If you have a chandelier (or any hanging light), that definitely says "dining room". I'd put my dining room table under it.

If you don't have a chandelier, you can still define the spaces with rugs. You could put a rug under your dining room table or a rug under your living room coffee table -- or you could do both.

If the back of a chair or sofa faces your dining area, this will also help define the space as a two separate areas.