If possible try and have a least 2 people on each leg, if only from a safety point of view.If there are two of you the navigator can concentrate on his job of getting you round, and the helper can carry windproofs and food/drink and make sure you are eating and drinking regularly. Plus the helper can take the split times at each peak.The navigator will already have his own map and compass with his list of bearings in case of misty conditions. The helper should also carry his own map and compass in case he can not keep up, and has to take a short cut to catch you up, or at least get himself to the next change over point if the mist is down. ( I've lost 2 helpers on two different legs in the mist, but they managed to get safely back to the next change over point. )
If you are navigating a leg section in the dark, its worth doing it a few times or try recce it in the dark to see how your bears work out, as things look different when it is misty dark and raining, plus you are straining to see where you are going.Write out your bearing in big text to see them better.