I LOVE Once Upon a Child. The only problem I have once I get in there is deciding what I am actually going to buy because there are so many great items.
The best way to use these certificates is to wait and combine them with a sale. Unlike most companies who do the daily deals, Once Upon a Child allows you to use these with any other promotion they are running. Last time, I waited until they had 70% off redline items and I RAKED it in.