"This small crystal tree doubles as a wedding centerpiece & a table number stand." I'd put some of these around my house (minus the number) made with small branch pieces found in the yard and a string of beads.
Candle Holders as Place Cards: Arrange a luminous table setting. Write guests names on strips of parchment paper and wrap them around votive holders, securing the ends with tape. Can do double duty as placecard holder and favor
Diva - Table idea for st. patty's day - LOVE the ribbon idea! Patrick's Day Party: a simple and classic St. Patrick's Day table setting - a great example of how to incorporate Pantone's color of the year - Emerald - into your next tablescape!
Tea lights set in mason jars: I like this idea combined with frosted mason jars which is just a simple spray can. Place multiple jars at each table. We can get mason jars of all differing sizes at Goodwills in the area.