Annie Sloan Dark Wax is a fantastic product for ageing your pieces.
Here I have painted two identical cherub pot holders in Pure White Chalk Paint by Annie Sloan. The one on the right has been aged with Annie Sloan Dark Wax and the one of the left as been clear waxed only.
The one that has been Dark Waxed has now aged the piece beautifully and makes a lot of the detail now more noticeable.
Keep in mind however if you are applying Dark Wax to always clear wax your piece first. This makes the Dark Wax easy to remove with the clear wax should you need to remove some or lighten it off in some areas.
Annie Sloan Dark Wax comes in a 500ml $40, 120ml $21.00 available at Paint Me White.