Agencies : Schedule reminders to call your recently-recruited candidates and clients to see how the integration process is going.
Company recruitment departments: Follow the progress of recently-integrated staff, share information about his/her mobility, advancement, aspirations etc. with operational staff.
Direct approach and head hunting:
Prepare your assignments using selections, by listing your target companies, potential candidates, people to source etc
Use social media to gather useful information about your target companies or candidates of interest and keep a record of your communication.