I wanted some goggles for a steampunk outfit, and my flying goggles looked too modern, so I looked for alternatives.
After consulting several tutorials, projects and cosplay websites, I sought out something to make the eye pieces from. In the end I used the tops of two 2-pint plastic milk bottles, and cut out a circle from the cap. I sandwiched two circles of acetate between the cap and the screw-top neck, and attached a leather belt from a charity shop to the eye pieces with upholstry pins and hot glue. A spare piece of leather was glued in as the nose-peice.
The most time consuming part was sanding down the raised lettering on the bottles, and spray painting (or rather waiting for the paint to dry) which was carried out over a number of days.