Direct Contact with your clients are extremely important. You need to have a schedule for regular contact with your clients and you need to reach out to your clients regularly.
General Email Tips: Do not send huge emails and attachments to clients – rather configure a web page with photos, videos – A DECENT LANDING PAGE (See this guide about page quality) – Your landing page (for your specials or for the page you want the client to see) should be fully responsive and adjust to all view ports (work on cell, mobile, pad. desktop,etc) – Also see this post about Landing Pages – or Special Offer Pages, etc
Reasons to connect with your clients: Competitions, Giveaways, Specials, Prizes, Deals, Offers, Industry News, Industry Opinion, Interesting, Entertaining
You can also call, visit and use any other reason or communication method, the main idea is to stay in touch with your client