Well, what do you want to do? I can start listing off fast food joints, grad school, industries, etc, but it really depends on the individual. What are your particular interests in physics, and what are your skills?
A number of possible career options are available to you, ranging from a service expert at MacDonalds to chief scientist at one of the UK research companies. And everything in between. What do you want to do? Earn money? Defend the country? Write papers and bathe in academic glory? Just make sure that if you want to do something with your physics, you're good at physics. There is fierce competition in the UK for those kind of roles...