Probably, you already quite well realize that before you remodel the interior, you must carefully plan everything. Good preparation will enable you to "play" with objects and space as you like.
First of all, try to combine the space used. For example, the bedroom should quickly flow into the kitchen, and the living room - in the hallway.
The role of clear boundaries is effectively performed by "air" partitions or multi-colored zones. It seems that there are no walls, but the functional section is noticeable.
The smaller the dwelling, the more important it is to use every centimeter of space. Any uncomfortable corner can be turned into a working office, a place to read your favorite books or for convenient storage of things.
In the course there is everything - even balconies or windowsills. And furniture that simultaneously performs several functions is simply irreplaceable in this situation. The main thing is to get to the point with the mind.