I've got full detailed instructions on my blog with recommended materials but here's the basics:

Materials: Birdhouse base, small stones (I buy bags of them at the dollar store), funnel for roof, silicone sealant to attach the stones, wood sealer.

Steps:

1. Start with a base. Here I used an unfinished birdhouse but you can also use a wide piece of PVC pipe, a jug, teapot...Anything with a the right shape.

2. If you're using a wooden birdhouse, first treat it with a wood sealant so it will last outdoors for many years.

3. Attach the stones using an outdoor silicone sealant (pick one that dries clear). Work from the bottom up so each row of stones rests on the ones below.

4. Add your roof and you're done!

More ideas: add a wee door; window boxes-create a whole fairy garden scene-; make the roof from moss or tiny cedar pieces or a folded licence plate...

I hope you'll share your ideas in the comments. Have fun!

PS: These birdhouses are intended as decorations only. See my blog for information on safe nesting boxes.