I've tried decoupage a few times and I like what I made for Usha for the Tea Coaster Exchange organised at NNC. All you need is ready-available tin coasters with cork backing from the supermarket or you can get them from craft and scrapbooking stores. Modge Podge varnish and your favourite patterned paper. This sounds like a simple tutorial already!
The decoupage tea coaster. A shoe lace bow with one of my favourite button cards!
My favourite pattern paper of choice was this napkin print I found at Jusco. Napkin decoupage will appear textured on a smooth surface. You can even try this method on a plain candle block. Measure and cut to size. Circular cutters don't work on napkins! So use your sharpest pair of scissors.
To cover the print of the original tin coaster, I apply a layer of modge podge and place a blank piece of paper on top. Don't try to rub off the motif on the top with chemicals, you may ruin the surface.
Decoupage is fun and easy, but it is actually time consuming because you have to wait for each layer to completely dry first before you can do the second layer. Apply another layer of varnish on top of the white base now.
Place the pattern paper on top of the white and apply another layer of varnish. Careful you don't tear the napkin. Do this in a singular stroke or direction. See the texture forming. Don't worry if the varnish seems white at the moment, it will dry clear.
Set aside to dry. And re-apply varnish and set aside to dry for a day or two. Keep fingers away from the surface!
The completed set. I used only 2 napkins and I picked all the birds perched on the branches from the pattern.
I used my circular cutter to cut freezer paper to individually line the stack so that it'll protect the coasters when I deliver them stacked tight in a box.