1. Play with a variety of textures like smooth vs. sharp or silky vs. rough.
2. Create layers - whether your coffee table is tiered or not, staking items such as candles and magazines or flowers and books, work to create a dynamic range of space.
3. Add color- whether you stick with a set color scheme or you use an array of complementing colors, adding a pop will brighten the room.
4. Not everything on your coffee table has to have a purpose, add a decorative object for a touch of sophistication. (Check out Jonathan Adler's collection, it's my favorite)
5. Vary hight and size - just like texture, make sure to work with an assortment of volumes and masses for diversity.
6. Bring it to life with some vegetation. Succulents are my favorite since they are the easiest plant to care for.