for this instructable you will need,
some craft foam (or halloween axe type foam of any kind that can be cut and sculpted slightly)
some plastic milk bottle caps
some black paint (acrylic or plasticote)
some gold, silver or bronzed paint
scissors a pen and super glue

Step 1: Drawing the Template

fist yo need to decide which coins your going to make and create a rough drawing, draw them a few times so you get a feel of how to draw them. then you need to draw around the bottle tops to make sure the design you draw onto the foam is not too big. then draw out the design/s.

Step 2: Cutting the Designs Out

no explanation needed

Step 3: Glueing the Foam to the Coin

self explanetry, then leave to dry for 30 mins or so less if its really good glue

Step 4: Base Coat

use black acrylic to completely cover the coin then allow to dry for an hour or so, if you use spray paint 15 to 20 mins is normally ok

Step 5: Dry Brushing

i didnt take any pictures of this process but its basically using a brush with most of the paint removed to build up layers to give it a tarnished effect.

Step 6: A Look at the Finished Items

this is just a bored evenings labour, if you want accurrate just take your time when planning, also you can just make loads of them till your happy with what you can create.