know the feeling. Last weekend I was in Brecon with some serious walkers. Managed to blister up my heel very early on in the day and had to bow out. So after fighting them off from taking my lunch I headed home. Only thing was they had the map. Fortunately I had GPS and used the track back. But looking back I could have ended up in real trouble.
So I would suggest plan your route and let someone know it too. Have an arranged check-in time. Think about what you are carrying, clothing - layers are good. Space blanket (mine's in my FAK) emergency BIVI. Food and water. Mobile, GPS + spare batteries (and maybe the user manual
). Map and a camera. A knife if you really think you need one, I know that won't make me popular on here, but if you don't need it don't take it.
Have fun and let us know how you get on