Give it 2 or 3 coats of varnish and allow to dry.
Note - If using wax or some none drying oils then the eyes will not stick to it.
If its for the garden then 4 coats of exterior varnish.
If using Oak, Chestnut or other durable wood it doesn't have to be varnished and will turn silver and age beautifully.
Glue on some wobbly eyes.
...say hello to your own tree spirit.