The key to beautiful tabletop décor is all in the details. There are so many decisions to be made: linens, china, silverware, stemware, centerpieces, candles, napkin folds, etc. With so much to think about it helps to imagine each place setting as a "hang out" spot for your guests. To make it feel special, like it is made just for them, I recommend napkin treatments.
There are so many ways to perfect this little detail. For understated elegance a single bloom that corresponds with the centerpiece, or a satin ribbon that matches the colors in the centerpiece, work perfectly. To make your napkin treatment serve double duty consider a miniature arrangement. Place a small bunch of flowers in a little vase on the napkin that your guests can later take home. Another option is to incorporate non-floral elements like fruit, or feathers, that tie into your overall décor.
However you decide to "dress-up" your napkins, this added touch will make your guests feel right at home during your reception.