Create a Micro-Pond
This is so simple. All you need to do is sink a watertight container (eg: dish, bowl, bin lid, tray, etc.) into the soil and fill with rainwater to a depth of 3-4 inches. It will be no bigger than a puddle.
Add some sand and gravel as a bottom layer (for bugs to burrow). Ensure the edges are shallow (allowing frogs to walk in and out easily).
Finally, place a rock/ large stone or two in and around the pond for shelter. Simple!