Usually do all but the most recent (so now, for example, everything before Jan 09 and Jun 09) on the screen (full screen so as to avoid distractions), followed by printing off the two most recent papers (i.e. Jan and Jun 09) and doing them the day before the exam (find it quite a good way of preparing for exam). All papers done under exam conditions, with no checking of the mark scheme until I come to actually mark the paper.