You could make something similar to a bouquet. Also you could take some pillar candles and wrap them with silk flowers. Also you could make wreaths using silk flowers. They come out beautiful.
It can be a good idea to combine flowers with unusual elements in your arrangement. Think fruit, vegetables, branches, rocks, shells, but even marbles, metal wire, gauze and such.
Always put silk flowers in something other then a traditional vase. Use pitchers, cups, bowls, odd free standing containers and craft figures. Shop at stores, clearance racks and yard sales for these unique vases.