Choosing a plant to accessorize is really no different than choosing artwork or frames. Due to their diversity in size, shape, color and texture - all these characteristics need to work in harmony with the rest of the room's design style.
So let's start with the pot! Your plant is the art - your pot the frame. The goal is to chose a container that compliments its surroundings as well as highlighting the plant you are planning to place in it.
Room design is also a consideration. Do you have a Country look? Then terra cotta style pots work well. Stainless steel for Contemporary design and brass pots fit well in Traditional style decor.
Placing that plant is another important consideration. In design nothing is done randomly, one must always consider Form, Function, Focal Point, Scale and Theme. It is not good enough to just fill an empty space with a plant, rather it must work with the rooms synergy to enhance not distract - compliment not dominate.