Decorating a Small Guest Room to Look neither Masculine nor Feminine

You don't need too much furniture in a guestroom so this bed on a platform would be ideal. It's the misty landscape scene, very much like a Chinese watercolour, that gives the room personality with a sense of peace. And  the bedlinen in this inky blue green is strong enough to appeal to male guest and yet soft and serene enough to make a woman  guest feel at home.

An Option to Consider:

How about a khaki and red colour scheme ? the more red in the room the more drama, the more khaki the more calm the effect and set the red and khaki against pale beige walls and beige carpeting.

You can get cushions or even upholster a chair in a geometric or modern-ethnic print that combines red and khaki in its colour scheme.

The Problem of Furnishing a Small Living Room to Create as Much Sense of Space as Possible 

Keep to light colour. dove greys and pale blues, the palest of apricot and rose or the family of sand and off-white. Be judicious in your choice of furniture. Choose a sofa and chair that are scaled down to suit small living rooms. Don't be tempted to put in bulky upholstered armchairs, no matter how comfy they look because they will be overpowering and dwarf other pieces. Also do not have too many pieces of furniture. Avoid clutter.

Do not have fancy drapes for the windows; light curtains or even blinds would be more suitable.

Add built-in or freestanding shelves for accessories and to accent vertical lines in the roomto give height to the interior spaces.
Use glass-topped coffee table and end tables or the new exiting perspex pieces. These take up less visual space than solid wood ones.