Can anyone give me tips on how to achieve the metallic gold buttercream pictured below[postimage id="2859" thumb="900"][postimage id="2860" thumb="900"]

I was advised by a Craftsy teacher that you can airbrush it.  It's probably the only way to get that metallic gold look. 

If you don't have an airbrush, the edible gold sprays on the market will do the job, too.  My order of preference is ChefMaster, PME, Wilton.  Multiple light coats that dry in between work the best, no matter which method that you use.

Thanks guys! I have an airbrush but the gold i have did give me the coverage i wanted. Ill give the others a try

I take it you meant the gold you have did NOT give you the coverage you wanted.  Then you need to give it several light coats.  OR maybe you have added too much liquid to the dust which again means adding another coat or two. 

The only other option is to paint it on.