aaf roundel1.cdr
You can try to look at
http://community.coreldraw.com/collaborate/w/howto/creating-a-distressed-look-in-vector
or
http://www.coreldrawtips.com/site/distressed-text-in-coreldraw
Try clip mask in PhotoPaint. There is millions of textures available free online to give you any result you desire.
The 50% off decal was made using the Artistic Brushes Textures category.