The aesthetics of the room is as important as its functionality. Comfort has many sources, and the mood that a place imprints on you is not to be neglected. If you turn to the help of an interior designer, he will know what to propose to you according to your needs, your style and, last but not least, your budget.
If you want to take care of the arrangement yourself, try to define first the style that represents you: classic? Mediterranean? Scandinavian? The options are many. It's easy to identify things we like, from furniture to decorations, but the key question is: do they like each other?
The mix of decorative styles is welcome - there's nothing wrong with that - but it's important to do some testing beforehand. The easiest and safest way is to "browse" some images with arrangements, and then see them as a whole, to find out if the pieces fit together. You can even make a collage, if the images that served as inspiration are from magazines: take scissors, glue and play a little.