1) Book all accommodation weeks or even months before the walk as their are sections of the walk where accommodation is limited.
2) We did the walk principally because I live to the west of the wall and also the prevailing wind is from the west, better to have the wind on your back.
3) If you think your maximum walking distance per day is 12 miles, you will probably be able to do 16 miles, or pro rata, given that you have to walk those extra miles to reach your accommodation. You cannot stop on a desolate section of the walk and say "I cannot go any further".
4) Take plenty of water and drink before you get thirsty. If you are gasping for a drink you have left it too late.
5) Although our walk was principally walking the wall, if you wish to visit the various forts and visitor centres then allow plenty of time for that.
6) The terrain of the walk varies from straight flat tarmac to lowland hills containing sections that could be described as mountaineering to finally walking through a city centre.