getting frogs to take up residence in my pond!

I have recently installed a small pond - smallest preformed shell - in the hopes of getting some resident frogs. I saw a young one hopping around in my garden once a couple of years ago which was what made me consider it ...
It was installed in July last year but apart from some daphnia last summer, no sign of life. Am I being impatient or should I get some frogspawn from somewhere. Or is it too late for that. If so what kind of place/person would be able to help me.
(The slugs and snails seem to have no reservations about colonising my garden and have recently chomped their way through 4 doz new marigolds - drat! )

 

Its too late for frogspawn, if there are other ponds in the area they will appear of their own accord. Plenty of weed helps, gives them somewhere to hide and also they need to be able to get in and out easilly. Dont keep things too clean either they like the odd bit of mud and slime

 

My garden is teeming with frogs but I only ever see one in the pond and thats after I've gone looking for it after I've heard it coaking. Don't worry, just because you can't see them doesn't mean they're not there.

 

We have an ordinary washing-up bowl in the corner of our garden, originally installed and filled with water for the cats and birds to use.
For several years we have had as many as three frogs at a time taking up residence and they have produced frogspawn which we transfer to a friend's large pond (think it would be a little overcrowded in a washing-up bowl).
The frogs also, somehow, squeeze underneath the bowl to hibernate during winter.