First and foremost you have to be grammatically correct in your presentation. There is nothing worse when trying to attract clients than poor (English) grammar and language skills. If you don't have these abilities engage with someone that can help. If you can't communicate effectively with your prospective customers they will not have confidence in your ability to deliver however technically able you might be. Next source a local (country specific) representative, provide examples of work you have previously completed, produce costed packages so clients know what your typical charges are and provide excellent customer care.
If you would like help to enter the UK market do make contact for further assistance.