Hi Sam, a few of the thoughts and things that worked for me, as I did my first Camino this year, starting 1 May, finishing 1 June this year.
1) dont plan too much, take it as it comes, some days you will want to walk far, others you wont.
2) I took 2 changes of clothes, and all worked well for me, half my sack was medication / suppliments
3) I placed my trust in toe socks (Injinji), and in my case, I am certain that they helped me in not getting as many blisters, I thought they were wonderful
4) buy boots 1 size to big,
5) I got out early in the mornings to enjoy the tranquility of walking on a lonely path, a wonderful experience particularly on the Messita with the sun rising on my back and lighting everything up
6) dont get hooked up with the same person for too long if they are starting to get on your nerves, as this can be restrictive, I attracted a "Klingon" on my first day, and it took me a week to shake him off as I was too kind to tell him I wanted to go my own way,
7) I have restrictive dietary needs, but I found no problem,
8) be kind and open, and you will be more than rewarded,
9) cherish every moment, even the inevitable hard times, as there will be some, but you will look back and smile at the oddest times afterwards,
10) keep in touch with those you shared the road afterwards, I have done this, and its only those who have done it that will ever understand the rewards it brings.
11) don't stress about backing too much, as you can get rid of stuff on route by donating it in Albergues, and some hard up person may be more than grateful....
12) blisters, you will get them, it doesn't take long to get used to them, and you will learn to live with them
My trip was a bucket list thing, and meant a huge amount to me as I have stage 4 cancer. I loved it more than I thought, and long to be back on the road if the body hold up. The people you will meet all have their own story, and there is something deeply personal and therapeutic in learning to share, not only the road, but your story, your food, your time, your time and your emotions.
In Ireland we say that a stranger is a friend we havent yet met. I think the Camino exemplifies this.
May the road rise up to meet you
Philip