How do you crochet a beautiful afgan?

What is beautiful to one person might not be to another. Find a pattern that YOU find beautiful. Practice the craft until you can make nice, even stitches. If there are specialized stitches or procedures needed, you might like to learn those as well.

In my opinion, you can make a very beautiful afghan with just basic stitches. There are many beautiful granny square afghans and all you need to know to make those are how to make and assemble granny squares and have a good sense of color.