I highly recommend the book "Origami Tessellations" by Eric Gjerde if you are interested in tessellations: http://www.happyfolding.com/book-gjerde-origami_tessellations
This video demonstrates how to fold a rabbit-ear triangle sink. It is a technique that is often used in origami tessellations.
The video also shows how to fold three rabbit-ear triangle sinks on a triangle grid. If you fill the whole paper with rabbit-ear triangle sinks, then you will receive the tessellation "Stacked Triangles" designed by Eric Gjerde. See a picture of one I folded here: http://www.happyfolding.com/gallery-gjerde-stacked_triangles