Coasters for favors are popular cheap wedding favor that your guests will enjoy, if you get it right, and by that I mean a favor that your guests will want to take home.
You can easily find themed wedding coasters, a leaf for a fall wedding with the words falling in love on the back or a shell for a beach themed wedding are both popular designs.
But do you think your guests will want to use one coaster? It may work out ok if their whole family are there as they will have a set but very few people will use a mismatched coaster at home.
If you are using your wedding favor coasters as part of your decorations then they will add to your theme, but they will often be overlooked by your guests as they may not think it is a favor for them. To get round this you can add a thank you note to the coaster or have your guests' name on the coaster.
The type of wedding coasters that your guests will enjoy are photo coasters where you could have the two of you in the frame or you could leave it blank for your guests to place their favorite photo or it could be of themselves enjoying the day, it is up to them.
Or they may enjoy a coaster with a funny quote, or a memorable moment that you have all enjoyed. You could have a LOVE coaster which your guests may use as their coaster on their desk and remember your special day.
Of course you could look at making your own coasters, you can buy packs of coasters that you can add your designs to and a funny quote. Wouldn't recommend making up your own coaster template as these can look a bit too much like a kids craft project. But by using blank coasters you could spray paint them and add your own design, maybe add the date and your initials on the back, your guests will love to add these to their scrapbook of your wedding after the day. Don't forget to cover them in varnish or use the white pva glue to make them as waterproof as possible. If you have access to a laminator then you could use that.