Why does my asparagus turn out too chewy?
I think you are over cooking them. Asparagus is a very delicate shoot, and it goes from nice and crispy to flat and soggy pretty quickly. Some people like it that way, but not me. I like mine hot, but still crisp.

The way I prepare asparagus with water is in a frying pan. Lay the asparagus out in the pan and just cover with cold water. Bring the water to a boil and immediately pull the asparagus out. It's ready to serve right then.

Sometimes I like to grill it, but that takes a little practice to get the timing just right and also not dropping them through the grill. :-\