Get out those red pens! For a twist on "error analysis", I like to use this template and work out some problems by hand. Some problems are correct, and some are incorrect. I make copies of the sheet for my students, and then, with red pens in hand, they "grade" the papers. Let me tell you - students REALLY enjoy taking on this role!
Some ideas of how to obtain authentic "wrong" work could include misconceptions gained through student work, such as a recent test, quiz, or homework assignment. This is a great way to assess prior knowledge as well! For example, rather than go straight to teaching operations with rational numbers, I used this template to work out some problems with fractions to see if students could catch my errors, and articulate why the errors were incorrect, and what should have been done instead. Very adaptable resource - enjoy!
Check out a recent blog post, featuring the use of this template at MathyCathy's Blog