To make your own clan, first tap on the clan symbol on the right bottom of the screen, next to the bag. A window will open and on this window you can create your clan. First give a name to your clan at the Clan Name area, then you can write a Clan Description. After that, using the Edit button you can create a crest for your clan. Then you can set the required level and clan type. Everyone can join a Public clan. If you set your clan to be Private, other players will need to send you a requirement to join your clan. And for the last step, tap on the Create Clan button. Beware though, creating a clan costs 700 gold.