I thought these lanterns made out of spaghetti sauce jars were pretty nifty, so I used what I had lying around (IKEA Rajtan spice jars I bought years ago and never used) to create a mini version:
(My picnic table is rustic, not dirty.)
The basic method is to paint the inside with glass paint (use a brush), and then bloop some gold paint on the outside in a design (use an applicator tip). Read the link for more detailed instructions and to see that I did not invent the term 'blooping.'
Here they are with some tea lights shoved in, although frankly this picture didn't turn out amazing:
If you want to try it, I have one tip to offer. The glass paint went on really gloopily the first time I tried it, so I recommend using only a tiny bit on your brush at a time and only doing a second coat (if desired) when the first is dry.