Choose Containers that are large enough to accommodate the root systems of your chosen plants. Smaller containers can result in a lack of moisture and nutrients, otherwise frequent watering and feeding will be needed.
Bush type vegetables such as Tomato, Brinjal are best grown in those containers which have greater depth (above 12 inch). Vine type such as Gourds, Beans needs even more depth (above 14 inch)
Some vegetables like carrot, Radish needs larger growing area as well, bed like containers at least 10 inch deep are good for them.
Containers having larger growing surface area with 6 to 8 inch depth are fine for herbs; like Coriander, lettuce etc.
Mix of sand, well-rotted manure & soil in 1:2:3.
Container should have holes at the base or in the bottom to permit drainage of excess water.
Dark color containers absorb more heat which could possibly damage the plant roots. In summer painting with a lighter color & vice-versa in winter will help your plant.