You can really draw your inspiration from the items that are already in your room. This will save you a lot of costly renovations and gives you a cohesive feeling in your room. Let the architectural details of your space determine your overall theme.
If you have ceiling beams you can go in a lot of different design directions depending on the color palette. The country and Southwest kind of design styles will use lighter oak or pine ceiling beams. If you want more of an elegant Tuscan or French country air then darker beams are in order. If you aren't thrilled about these items at all then just paint out the natural wood tones with a bright white for more of a modern kind of look.
You also can go in more of an industrial direction if you have a loft style of apartment. If you're lucky enough to have a brick wall then really highlight it by bringing in neutral furniture and lots of lamps so that it doesn't seem too dark. The same color inspiration can come from your concrete styles of floors.
It's also possible to use craft projects for living room decorating ideas. You could just find unusual ways to use a damask print. If you have wood floors try stenciling it directly on the floor. This is a trendy print right now that also has a classic print to it so it will probably give you a lasting look depending on the color palettes that you choose to go with.
Another area where you can use a damask print is right on your furniture instead of going with your typical wallpaper. This is going to seem very elegant but you do need to choose a piece with a flat surface such as an entryway table. Then mix in solid colors of white and black furniture to tone down the pattern and use what you already own.
You can also create a bold look with your wall color if you have a lot of white or taupe furniture in the space. This means that your room can handle a daring color or even emerald green walls. Almost any color will work even if it isn't a trendy item. The key here is to create a tropical look with gauzy light materials.
You can also use traditional materials in new ways. For a lodge like effect try taking slate tile all the way up to the ceiling. You could use the same tile in contemporary design as long as it was oversized. Skip the mantle though in this case. You can also get smaller tile designs which will really be more traditional in style.
You could even take the slate inspiration quite literally even if you can't afford to bring it into your space. Try mapping off different blocks and paint one wall in these tones with various faux finishes. You could even make it more neutral with shades of brown instead of traditional orange.
As far as your furniture goes you can stick with classic silhouettes but put your own personal spin on it. A chesterfield sofa has a lower back and dramatic arms. If you want it to feel more modern look for two cushions instead of the more formal cushions. This can also help to break up the tufting that is so integral to this design style. If you find a version that has fading, even if it's at a thrift store, you can still work with this. Worn leather is a hallmark of the rustic design style. It can be very elegant looking too if you pair it with a shabby chic floral print accent chair.
It's important to find furniture that's going to work in smaller spaces. A settee is a great option for this although it isn't as overstuffed as you might be used to. It can even have a wingback design style with fun side to it. Sure, it's a classic style for a chair but it's unusual for larger pieces of furniture. This can be pretty inexpensive and it's going to be a lot more elegant looking than a futon. Modern versions don't have arms which is going to be one of the only ways that you're going to be able to stretch out and relax on one of these smaller pieces.
A cottage design style is going to be slightly formal and feminine. It's going to use painted brick both on walls and fireplaces instead of more of a traditional brick red. Fabric prints are essential for this room and it will even work on accent chairs. You can bring in this design style if you have leather sectionals or microsuede sofas but it's just that much more essential to go with formal fabrics on your other furniture pieces. This is also one of the few design styles where you can get away with using tablecloths, even on your end tables. Otherwise this would be dated, but skip a lot of ruffles. Instead just stick with burlap or even faux linen.
You can also go with more of a suede finish on your walls. This isn't going to be the outdated color washes that were popular a few years ago. Instead it focuses on pouncing and stippling. This will use tones that are closer in tone to each other. This is going to be a subtle rustic look or just a way to make brown walls more interesting. Skip a lot of the other leather furniture tones. Instead go for sleek black end tables.
Sophistication is also important when it comes to unusual living room color palettes. Instead of lavender try going with an aubergine that will be darker and might have a little bit more red to it. Just make sure you get a funky vibe with a leather shag rug or a retro inspired wallpaper. However, skip mixing in lots of greens or yellows. This will seem too retro. You'll want to instead go with metallics, mirrored pieces and white furniture to make it more contemporary.