How do you create a partner marketing strategy, outside of cold emailing, cold calling, and trade shows?

Focusing on the right partners and building an integrated co-marketing plan are critical. Sponsoring events is part of the game in partner marketing, but I'm not sure how much of your time should be spent sending out cold emails and cold calls to prospects. 

It sounds like you're working with biz dev and alliance teams to identify the right partners to work with. I'd recommend starting with a handful of select partners, learn about how to leverage the resources within their ecosystem, and build relationships across their org - before going wide and cold emailing partners to join your ecosystem.