My answer to question asked in a private space:
Not super experienced in the space but this is what I observed when it comes to building relationships with family office (assuming you already have an introduction or chatted with them at least once):
1. Does the family office co-invest? If so, send them some deals that they might be interested in and build relationship that way.
2. Do they care about investment thesis / mission? Send then weekly/monthly/quarterly update emails. Keep it short and to the point. (We usually have two touch points in a quarter with them. Once with funds quarterly update and another with a generic newsletter we send out to everyone that we know or care about the fund)
3. Figure out the personality of the family office. How do they do their things?
When you are in contact with one office and things are going well doesn’t hurt to ask for an intro to another office that they might know or an event that might be useful.
Family offices are tricky at the end of the day. They can help introduce you to others in the network or block you from going to others when raising money.