How to prepare banners.
This can be done using as a tool any photo shop program; in this example, Fast and simple Irfanview is easy to work with.
First select the banner of your choice (I select this one).

Editing the banner using "Irfan View" .
To insert a "Message", select the desire area dragging the mouse on the banner like this:

Click edit, then insert text into selection. And do the same to the other area.

It will look like this:

To do this you can use any photo shop.