Click on your pen tool on the bottom-left navigation bar. Also, make sure your layers view is visible. If it's not, just go to VIEW-->PALETTES-->LAYERS.
With your pen tool, draw a wavy line in whichever direction you'd like.
Click on your Text Tool, 
which is located on the bottom left part of your navigation. Then, just type in whatever texts you please.
And now, you're basically done. To get rid of the line, all you have to do is go to your layers and click on the eye next to the "Vector" section.
OK, you're done. Now go buy stuff from my shop.
If you have any trouble please don't hesitate to ask at mayra@poison-drop.com.