Go find a beautiful background!! Save it.
Open power point, after you have chosen a background,
click on INSERT, click on 'picture', choose your picture and ok.
Using your mouse, click on one of the little buttons and pull the background out so it fits the page.
Go up to INSERT again, click on 'text box'.. add your text, size it, change font, whatever. You can add as many text boxes as you want. Put them all the way to the left and to the right of the page because the twitter info is going down the center.
The twitter page is fairly small so when you are done playing, put your mouse on the background picture (while still in PP) and right click, scroll down to size and position, size should be 11.75 X 19.17.
SAVE AS > .jpg
Go to Twitter, settings, design.. choose 'change background', browse to find yours, click ok. It may take a few tweeks because the sizing is funny. I found the first one was WAY too big so I had to go back into PP and make it smaller but the last size I came up with was the one I mentioned above.
have fun, I expect to see tons of new beautiful backgrounds now!!