A farmhouse dining room is a very welcoming space. It also is a theme that will work well if you have a combined kitchen and dining room area. It's a place where your family can gather and eat home-cooked meals or just ponder over your take out. It can of course work in a classic country house but you may also want to use it as a way to add warmth and character to a condo or apartment.
Add in natural elements. A farmhouse probably would have wide plank floors and wood ceiling beams. Keep the walls a bright white or a sunny yellow to compliment the dark wood tones and to prevent them from overtaking the room. This adds a lot of architectural interest and can work with other design styles and directions that you choose to go in later on.
Consider your furniture carefully. This is a very specific theme but it doesn't have to be expensive. You can find dining room tables made out of lighter wood planks or just paint your existing table a soft grayish blue that will instantly seem weathered. If seating is an issue for you then take out the chairs and try a bench. This isn't always practical for your company so make sure that you have chairs with backs on them at the head and the foot of the table and the kids can always just sit on the benches.
Bring in rustic metal tones. These include antique brass, oil rubbed bronze, and rust. You want to use these on all the fixtures in the room including the lighting so that your space has a sense of history to it. This will make your home feel like it's been around for while even if it was just built last year. You get the chance to add in some character and your own design style and personality to a plain white box.
Decorate with stone elements. This may be a fireplace if you're looking to add a focal point in your dining room where you could bring in engineered stone on one of your walls. This will make your home fill more like a country farmhouse and will also work as an area where you can really bring in a lot of different natural colors. You can even accomplish this simply by using the concrete stone around a few of the pillars in your space.
Farmhouse furniture is very hardy and substantial. It should be made out of real wood even if it is made out of a painted wood. Farmhouse chairs usually have a curved back with spindles and are very comfortable. You can also bring in a hutch or pie safe for extra storage or a place to just display your favorite china.
As far as color palettes goes for a farmhouse dining room try and go with a very muted palette. This doesn't mean that you have to stick with neutral or boring colors. You can mix in a lot of blues, reds, yellows, or greens. You just want to make sure that these colors have more of a weathered appearance, you can even put a glaze on top of them to give your room a sense that they have been around a lot longer than it actually has.