If you have a large tree in your garden it might provide the perfect place to construct a bench. Think about building a simple garden bench around the base of your big tree. You will want to leave a bit of space for the trees additional trunk growth.
Depending on the type of tree you are circumventing, it may very well provide the seating with some wonderful shade. It is preferable that you build the bench in keeping with the dimensions of your garden space. So, do not go overboard if your garden is teensy, or it will feel unbalanced.
This does not mean that you should avoid having fun with the construction, and detail. For a soft touch attach wooden gingerbread to the edge of the seat. Or if you are looking for a surprise, paint it the boldest colour you can find.