This week I gave my students a take-home practice test, drawn from a TAKS prep workbook. It is the same length as the real test (52 questions) and covers everything. For your purposes, you could use any full length practice or release test as your source.
Students work on the test at home or whenever they are finished with their daily classwork. They have about a week to complete it. More importantly, their grade is based on making corrections and resubmitting it after I've checked and returned it to them. I don't see the point in giving them practice tests in a high-stakes environment; they've done enough of those already, and since we have the luxury of time, there's no excuse not to go back and figure out how to do every single question on there. If that means everyone resubmits the practice test and gets 100, so be it. The grade itself is inconsequential--did they learn what they needed to learn?
The only thing I added to the test, besides the idea of automatic retests, was a key (see above). Last year my students were lacking in test taking skills, especially the idea of skipping difficult questions and returning to them later. So I went through the test and marked off easy, medium, hard and recently or not yet covered questions. This was subjective but based on my impression of their grasp of each topic when previously taught.When comparing last year's original version of this test, I found that I was marking questions "easy" this year that were "medium" or "hard" last year. My students seem to be better prepared and more hardworking this year--but I'd like to think some of that change can be attributed to my growth as a math teacher. In turn, my expectations have risen and I expect them to find more of the test easy.
I told my students to use the key to guide them, starting with the easy ones before working their way to the hardest. "This is what I want you to do on the real test," I told them, "so you won't let a few hard questions stress you out and affect how you do on the rest of the test."
I know students appreciate this kind of help, because last year students of other teachers asked me for the take-home test because their teachers hadn't provided one. This year, I convinced all of my fellow 9th grade Algebra teachers to give students the same opportunity, so I know each student will get the practice they need.
This idea and many others can be found in my book, Ten Cheap Lessons: Easy, Engaging Ideas for Every Secondary Classroom. It's available on Amazon and B&N today.