You can put flowers in just about anything. An antique watering can, a tin can, a plastic cup or glass, the opportunities are endless. Some containers work better with water and the flower stems cut to an appropriate length.
Shallow containers work better with floating flower heads, for example a shallow bowl or votive cup.
Baskets, ceramics or clay pots work better when lined with a plastic container, as do oversized or extra large containers. (Liners can be placed inside the larger container to reduce the size and weight need to fill the entire container.
See Also
Alternatives for Floral Foam