Sushi is a sample of minimalism of the Japanese cuisine, since sushi commonly uses a small number of ingredients, combined in various ways. You should know that the best sushi preparation requires a use of the highest quality and freshest ingredients, complete attention to the smallest detail, a harmony (as in each Japanese art), and a proper understanding of seasonal and local fish.

The main idea of the sushi preparation is a practice of preserving fish with salt and fermenting with rice, a process that can probably be traced back to seafood-preserving methods, used in Southeast Asia, where countries have a long history of rice cultivation.

A common ingredient in all different kinds of sushi is sushi rice. A sushi variety arises in the choice of fillings and toppings, the other condiments, and in the way they are put together. Some popular varieties include:
Nigiri - small rice balls with fish or other toppings, some of the most common ones are tuna, shrimp, eel, squid, octopus and fried egg.
Gunkan are small cups, made of sushi rice and dried seaweed, filled with seafood, etc.
Norimaki is sushi rice and seafood or other ingredients, rolled in dried seaweed sheets. There are countless varieties of sushi rolls, varying in ingredients and thickness.

All sushi is commonly served in a minimalist Japanese-style, geometric, wood or lacquer plates, which are mono- or duo-tone in color that keeps with the aesthetic qualities of this cuisine.
The best sushi is made with white, short-grained, Japanese rice, mixed with a dressing, made of rice vinegar, sugar, salt, konbu and sake. It is cooled to a room temperature before being used. In some fusion cuisine restaurants, short grain brown rice and wild rice are also used. There are also regional differences in sushi rice and an individual chef certainly has his own methods. To prepare the best sushi, it is important to use the freshest and high quality fish and a professional chef can always recognize the quality of fish, as well as its freshness.

As a rule, sushi in traditional sushi restaurants in Japan is expensive, since the chefs use the best ingredients for its preparation. Hence, do not look for a cheap place to enjoy the taste of the best sushi; cheap sushi can have an overly fishy taste and a bad texture. The best sushi in Tokyo is served at the restaurants of Tsukiji Fish Market, which is the biggest wholesale market in Japan. In Osaka, you can visit the Dotonbori area, which is Osaka's best eating district, featuring a number of excellent restaurants that serve the best sushi. It is located in the center of Osaka. Conveyor belt sushi/sushi train restaurants are also a popular way to eat sushi in modern Japan.

Finally, you can easily prepare any sushi varieties at home if you buy all necessary kitchen equipment for its preparation and strictly follow the original Japanese recipe. Luckily, free recipes of sushi and culinary books for sale are abundant on the web. For instance, there is a book The Best 50 Sushi Rolls by Carol M. Newman on amazon.com that describes the intricacies of the sushi rolls preparation.