Help me to increase my client base!

Like many people, I'm looking for ways to increase the number of (Health & Safety) clients that I have.

How to do this?

• Direct mail?
• email campaign? DOING, MailChimp
• (Even more) Networking? LIMITED POTENTIAL FOR THIS
• On selling to existing clients?
• COSHH (Bio)
• MHO to Charn F
• Targeting bigger clients? TRYING TO DO SO
• BL
• Shef U
• Various London FM Co's
• Web-site makeover - DONE
• PR campaign?
• Seminars? - DOING
• Teasing out suitable client contacts from existing sources? - NEED TO DEVELOP FURTHER

Ideas welcome