Patterns for stimulation are easy to find and inexpensive to to obtain.
I personally like to sit on the floor with my infant and drape him/her over my lap in a prone position so that her face is looking into a open book. The picture, or just the black and white lines of print on the page create excellent patterns, which the child can enyoy. At the same time, babies benefit from the tactile experinece as do the parents.