Tips From the Front Lines

Right now I’m working through revising a novel I wrote in high school.  It was my first such attempt and I’m very fond of it.  I still think it has a good premise, but looking at it now with nearly a decade of additional writing experience, some of the writing seems laughable. 

I’d like to share a tip every week that I’m gleaning from this process in hopes that others, especially you young writers, will not develop bad habits that will have to be broken later.  
Tip #1: Vary the beginnings of your sentences.  If you’re not careful, your writing can start to sound like a “Tennis match”. 
Hans smiled. “I thought you would say that.” 
Anna scratched her head. “Of course, you can read me like a book.” 
Hans took a step back. “….” 
Anna twitched her nose. “…” 
Person one’s turn, person’s two’s turn…it starts sounding stilted.  Switch things around, put the dialog first sometimes, don’t use dialog tag sometimes, whatever you need to add flavor to your writing.  
Have you seen this in your own writing?  In the writing of others?