From Silence is Golden
Check in with your clients and see how they are going. No need to make a big plan and over think it, just send them an email or give a quick call and ask how they are doing and see what's new. If you like, you can tease a bit of good news that can be useful to get a reply.
When your client speaks, really listen to them. One way you can be a more active listener is taking notes and repeating back key points during the conversation and/or in a recap email after a conversation.
A partner is someone that knows your goals and actively works towards them with you. If you want to parter with your clients, you need to know what their goals are.
Try this simple call framework to help understand your client's goal and to help them see you as a partner: