Advice for a career in International Relations

I have graduated University with a 2:1 in Politics and International Relations I would like to work for international development organisations, the foreign office, embassy work - that sort of avenue. I am lacking experience in this field and was wondering how do I build up experience? Unfortunately I was not accepted on to the foreign office grad scheme (I will try again next year). Are there any other routes? Any other general tips about a career in IR are also greatly appreciated. Many thanks Elizabeth