Betta Fish can survive in almost any container of fresh water, and for this reason Brandy glasses and other small containters have been a popular "home" used by people over the years. However, Betta Fish will thrive much better in a full-size fish bowl or small aquarium (10 gallons is a good size, and perfect for breeding).
Also, it is a good idea to have some minor filtration in the bowl or tank as well. Sponge filters are popular and a good choice because they'll fit nicely into any space, are cheap and very easy to maintain. Plus, if you'll be breeding your Betta Fish sponge filters have no suction, unlike pump-powered filtration, so won't pull-in and harm the weak baby Bettas.
When cleaning your bowl or tank and decorations, never use soap. It is nearly impossible to completely rinse off and can harm your fish. Warm water and an untreated plastic abraisive brush will work just fine.
Bettas, much like Goldfish, are hardy pets and can live and thrive in nearly any sort of bowl environment provided the water temperature remains moderate and you keep their home clean of uneaten food and droppings.
Even a simple large glass, like a Brandy Snifter, can serve as a suitable home for Bettas.
Still, with such a beautiful animal it's really a shame to not show them off in a slightly nicer way. A simple, small fishbowl with some marbles and just one or two decorations will go a long way to providing you and your visitors with an even more pleasing experience when viewing the fish.
Also, to better ensure a healthy life for your Betta, it's wise to have them in a bowl or tank with an air and water filtration system.
While Bettas can survive by surfacing for oxygen when needed, this does place more stress on the animal that can have a negative impact on them over time.
Also, with no constant filtration system you will find yourself having to manually clean the bowl and swapping out water on a more frequent basis. So, not only is it better for your fish, but it's also easier on you in the long term.
....Betta Fish Care
In addition to the minimum filtration suggested above, you'll want to change out about a third of the water in your Betta's home every other day, replacing it with fresh water that has sat for at-least 24 hours since being poured from the tap.
A good tip here, is when removing water for the change outs, use a Turkey Baster and suck up water from the bottom of the bowl or tank. This way you'll also remove any uneaten food that has settled to the bottom, which will turn the water cloudy and can lead to potential illness for you fish if left laying there.
A lot of people like to put Lily roots in their Betta fish tanks. These are nice decorations and the Betta fish will even eat from them, but you shouldn't consider this the primary food source for your fish. Bettas eat from the Lily root out of desperation, meaning they're under nurished and at risk for their health, you wouldn't want to make your Betta fish sick or have to deal with Betta disease.
You should feed your Betta daily but don't give your fish food too much, taking care to use food that is clearly marked for Betta Fish. Freeze dried worms (mosquito larvae) and live shrimps are also good for your Betta, and they love them!