Always follow up contacts, job applications, letters, emails and telephone calls that you have made and sent. Did they receive your letter, application, company profile and CV? Offer to meet for an interview. Make an effort to visit the company’s stand at a trade show and introduce yourself: this can help them to remember you. It is always worth meeting potential clients even if at the time it does not result in work. One company contacted me two years after I was interviewed. They remembered me and liked my work: it was not exactly what they had needed at the time but was just what they needed at a later date. I have worked for them on several occasions since.