A little and increase

The easiest way is to use wallpaper with vertical ornaments. But be careful, do not choose too bright colors, since the ceiling will seem lower, and not higher. Therefore, the drawing should be designed in pastel and light shades. And if you decide to paint the walls, then do it to the ceiling, do not leave any gaps. So you lift it a little and increase the size of the room. In principle, it is undesirable to use some edges, but if you still want a finish, then choose thin skirting boards. Another option that appeared relatively recently was wall painting. The technique as «Damage» is very popular. That is, you can apply the image you have chosen to any surface, in the end you will get a voluminous pattern. So, you can portray a forest with beautiful clouds.