The first thing i would say is something you have probably heard before-pack light.i took 7kgs without water and it certainly got heavy after 6-7 hours of walking.in my opinion extra shoes are a waste.some of the refugios are dumps.the one in casar caceres is one.the beds are within 1 metre of the toilets and overcrowded.but the ones in galicia are very good.the vdlp is much less organised than the french way.i travelled with a dane who had walked the french way 3 times and he said he would never do the vdlp again-too tough and very little infrastructure.some times there are no bars open in the mornings so have some food handy.shops open late-if you can find them.
relax-some people were up at 6am to walk 20kms which meant they reached their destination at around noon-why? they then faced 10 hours of boredom.you shoudnt have the problem of heat in september so leaving early would be pointless-sleep in,its not the army.spain is very cheap so meals are reasonably priced-if a bit monotonous.
learn some spanish-as far as english is concerned you may as well be an alien-noone speaks english.
some stretches are tedious-miles and miles of vines and olive trees,or corn/wheat fields.
having said all that it is a great sense of achievement but it is hard,250kms longer than the french way without the facilities-some stretches have no bars,towns or anything for a drink
be prepared;i walked 28kms to an embalse with a new refugio only to find it closed ;for technical reasons; so i had to walk 12kms to the next town.the concept of the closed refugio advising the previous refugio that it is closed so pilgrims should avoid it seems an alien concept in spain.
do have a good time-i'm sure it will be eventful and memorable-let me know how you get on!
kevin