In reply to LancasterB:
70+ QMDs should hopefully mean you have a good breadth of walking experience in different terrain, conditions, people etc so you should have most things nailed.
My advice would be to don't walk too fast and even when you are micro naving in the dark in crappy weather don't forget to keep checking back on the others (if you have done most of your walking solo or with mates then these are classic mistakes, my mate got an absolute bollocking on his assessment for walking way too fast!).
My pace is 60 for every 100 metres so I would stop and check back at a set point, say every 15/20/30 paces depending on viz. It shows you can nav and look after your group.
Agree with not tucking map in to waist belt, it is a bit amateurish looking. Again with your level of experience you should be using chopped down maps/small pocket sized printouts that can be shoved in pockets out of sight. It doesn't look good if you always have a map out as it can show a lack of confidence.
Don't worry about making mistakes, we've all made mistakes in assesment at some point. Just keep your head up and move on, it's a 5 day assesment so you normally have time to make up any mistakes.
Finally just make sure your flora and faunae, geology and history is all up to date and relevant for the area of your assessment. I used hostile habitats for Scotland and revised a day before assesment on the hill by walking around and looking at plants and matching them up with hostile habitats so I knew how to spot them in the field and also learn the name/history/usage etc.
Enjoy the experience, you will have an enjoyable week and make new friends no doubt. Best of luck and let us know how you get on!