Most developed nations have all kinds of barriers and quotas in place to make it difficult for aliens to fill jobs that might otherwise be filled by citizens.
Sometimes the right connections, company sponsorship, etc. can get you in; but if you're imagining just flying to the UK or wherever and getting a job, that's not possible. Even if a company there wants to hire you and is willing to jump through legal hoops it still may not be possible.
You don't have to work in a developed nation to work with developed nation clients.
Try and target yourself to those clients and avoid the local clients like a plague. It has been my experience that if you want to break into more profitable territory you need to break away from local clients completely.
