Creating your own Clan is easy! First, open the Clans section of the game from the flock screen. Then, tap on "Create a Clan." You'll now see the window where you can create your Clan. Tap on the section "Clan Name" to type the name you want for your Clan. Similarly, tap on "Clan Description" to write a quick description about your Clan. To the left of both of these sections, you can tap to pick a badge for your Clan. On the right side, you can pick a location for your Clan. Please note, you can not change this after creating the Clan! Lastly, you can also pick the Clan type. An "Open" Clan means anyone can join your Clan, while if your Clan is "Closed", potential members can send requests to join your Clan that must be approved by you before they can join.
After you've chosen all your options, all you have to do is tap Create! The cost to create a Clan is 350 gems.