Board Thread:Support Requests - Designing Your Wikia/@comment-3312658-20140404123623/@comment-1330470-20140404200813

You can make a good one in Photoshop, Paint.NET, or GIMP - the second two are free and I personally use the third.

There's not really a way to explain how to use these programs concisely in one message, so I can only really say practice over a period of time, maybe Google some general tutorials, and if you need a wordmark now perhaps ask a member of the community.