If you have a large entryway with tall ceilings, a great way to fill the space is with a round entryway table. Then create height on the table with your accessories to fill the vertical space as well!
A great trick to decorating your mantle is to let the art do all the talking. Keeping the accessories to a minimum creates a nice, clean look. The color here all comes from the artwork, which takes up most of the negative space on the mantle itself!