It really just depends on what you like; it's hard to look at a space and give suggestions blindly. As an example, when I lived alone, I preferred a more simple and industrial look. My furniture was either gray or dark blue, and the harder pieces were a darker-colored wood so that everything could be interchanged in each room without clashes. In the house I'm in now, we tend to focus more on pieces that have storage.
It helps to find photos of rooms that you like, and to remember what you're using the room for. I have a book of sketches of the spaces in the house so that I can easily refer to it if I happen across a piece of furniture or storage item that I like. I just open up the book, look to see if it would fit in the particular space I'm imagining and go from there.