I love shadowboxing but understand how some people find it boring or tough at first. Here's an article I wrote about how to mix things up by working with a partner.
Warning: Don't do too much shadowboxing! I remember a time when I used to do 30 minutes every morning and 30 minutes ever night (timing myself with the oven timer). Pretty soon I couldn't lift my arms away from my sides. Thinking I hurt my shoulders while grappling I kept on shadowboxing every morning and night until the pain became excruciating and I finally figured out that all of the punching was causing it lol.
Didn't people used to get made fun of for doing partner shadowboxing?
FWIW, I dig that exercise and it's a great way to warm up a class before you get into actual sparring (if you don't take the time to do it properly, the first couple rounds look like partnered shadowboxing anyway....)