This pattern offers a square motif I have been making since childhood, and a photo tutorial on how I joined as I crocheted. It is a highly customizable pattern. I wrote the pattern by letting my 2 yr old pick out whatever yarn she wanted and going from there.

Gauge is not crucial for this pattern, it makes a twin sized blanket - a little on the large side. I used just a little of the second skein of each red heart skein, but my tension is typically fairly loose so it is possible that you will only need one of each color.