Laurens, I think it very much depends on your background (ie experience and studies). I think most people who work as consultants on development projects have accumulated experience in a very specific (and relevant) field or in a particular country/region. Other people I know who have moved across from other professions have first done a relevant masters degree (eg international development studies, dev economics, health). Others have started working directly for NGOs (but not in a consultant capacity) in London for pretty low pay and doing more menial work in order to get a foot in the door that leads to more interesting work (but still not for good pay).
