It depends in if you are happy with a functional decor or want to build something nicer and more natural looking to include set-ups with live plants in the dry and wet areas. This care article has some nice information and provides various decor ideas in the housing area: Frog Forum - Fire-Bellied Toad Care and Breeding - Bombina orientalis and relatives.
To go functional can use turtle docks or pieces of cork bark to provide the frogs with dry areas and you are pretty much done. You can also add a "dam" with a glass pane and silicone glue to separate dry and wet areas in the tank. Going up in complexity you can build a false bottom set-up with plastic egg crate and have dry substrate areas above the highest water level. The ultimate set-up would include live plants in the wet and dry areas with suitable substrate for both. Lot's of information is available in the Vivarium Section.
If your water area is going to be permanent (not a daily changed water dish); strongly recommend use a filter to increase the water quality and reduce the need for daily water changes. Filter can be something as simple as a foam unit powered by an air pump or an internal powered unit. If going for later; myself use the Supreme Ovation filters made by Danner. Good luck!