This achievement pops when you successfully create a level and save it. To do that, follow these steps:
Choose Play/Create Custom from the start screen
Press the Editor button on the right side of the screen
Skip the tutorial
Use your finger to draw some pieces (I chose to draw 5).
Make sure the pieces go 7 feet above the pass line.
Choose Keep Changes
Choose Exit again.
If you have any questions or run into any problems, let me know!