Using you finger tip apply some gold rubbing paste to the raised bits of the wand. You can use a gold marker or gold gel pen or gold modeling paint. The best stuff is the art store product that is designed to be rubbed on with the finger tip and then burnished a bit, but any gold paint will do.
For one of my kids wands I used a bit of silver leaf to make some very highly reflective parts metallic looking. It was a brilliant effect. This is a bit more complicated in that you have to have gold or silver leaf and you have to paint a thin layer of gold size (a model makers' and artists' liquid glue that dries slightly tacky) on to the raised surface first and allow to dry for 2 hours and then apply the gold or silver leaf with great care (it is sooo thin) and then remover the excess with a very fine brush and burnish up with a soft cloth. The effect though is truly amazing, like real polished gold or silver (which is what it is of course). Gold or silver leaf is very cheap but you need to get it from a good art shop or from the web.