All of my students have exams on their minds right now.
Students turn in their answer sheets after thirty minutes, but they keep the question sheet.
Another option is to ask for student volunteers who will meet with you immediately after the test to identify any specific problems with the exam. Or you could set up a student exam review committee. This is only possible, of course, in small classes. Ask students to write a question or pose a problem that they were well prepared to answer. A variation is not to give students a take-home test but instead to schedule, some days later, a repeat test containing equivalent items.