I found this pretty and thrifty wedding candle craft at I Love to Craft. Because you’ll be using stickers, it’s very versatile.
If you’re going for a Victorian feel, look for soft roses and if it’s a winter wedding, maybe white snowflake stickers on blue candles.
Consider creating the design on a hurricane shell so that you can pop a votive holder inside. That way, you can actually burn the candle without worrying about setting the stickers on fire.
See Wedding Candles for full instructions.