There are many different ways you can set up a fish tank for bettas. How you set up the kit depends on the product itself. In most cases, the tank and its kit will have clear and detailed instructions that will help you set everything up if you follow them correctly. The main part you need to take care of is to set up the tank itself. After you are done with the tank set up, you can proceed to set the decorations and gravel. Afterward, you need to take care of all the electronic accessories, like the lights or filters the kit might have. You also need to leave space for a heater, if you plan on adding it later.