Chamfer the selected edges. Use an average amount, not too small which will result in sharp edges and not too wide which will give you very round edges.
This is I got after adding a MeshSmooth modifier with 3 Iterations to the modifiers stack of our object.
For the seating pillow use another box. Convert it to an editable poly and adjust its vertices so it matches the main chair frame.
We have just opened our tutorial directory! Feel free to submit tutorials hosted on your website or other online tutorials that you think are worth mentioning.