Sometimes, quite inexplicably, my lips will suddenly be really dry and sore. Whilst most lip balms are good for when your lips feel a little bit dry, most don't seem to cut it when they are constantly dry. However I have discovered a little gem!
Clarins Moisture Replenishing Lip Balm is an absolute saviour. It is the ultimate in hydrating lips and it really works. It stays on for ages, you can feel it working, and if I leave it on overnight whilst I sleep, when I wake up my lips are super-soft.
I always carry this in my bag, and it would definitely be one of my essentials on a desert island. I really can't recommend this enough! Although fairly expensive for lip balm but it is definitely worth it.