As you have probably worked out when doing your Duke of Edinburgh you have to carry everything around you need on your back pack. It is heavy! SO here are my tips on how to make it lighter or manageable to carry:
1. Only pack what you need
I think this is quite a obvious one but it goes without saying. Girls you don't need lots of make up for this. You don't need a huge amount of clothes, you don't even need pyjamas! Just take necessities.
So this may sound a bit weird but where the bags are so heavy it can dig into your shoulders when you are carrying it so it is a really good idea to tape sponges to the insides of the straps to make it softer and not as uncomfortable on your shoulders. It won't make it completely better but its a start
Wear clothes that cover your shoulders in colder weather this is a lot easier as you will probably be wearing layers but in the summer at the least have t-shirt with a small sleeve on it.
Pack your bag in order of what you need to clothes for the next day(s) put at the bottom as you won't need them for a while, first aid kit and blister kit at the top of your bag! P.s Don't be surprised if you need your blister kit for your shoulders.