Currently looking at my frog pond, which has a fat male pobblebonk croaking happily in it.
My pond is a 350l pre-fabricated pond, which has a variety of plants - all bought from bunnings. The plant is surrounded in lush plant-life, and I have seen at least 3 frogs in it in the past week.
Be sure to include an easy-to-get-out-of ramp, so no frogs drown. I use a small natural log slanting up one side. Filtration is not required given there is enough plant life, but what movement is a good idea to prevent insect and mosquitos breeding.
No fish - they'll eat the eggs.
I recommend a mixture of swamp and floating plants - underwater plants are optional, but do provide good hiding places for tadpoles.