If starting as more of a generalist PMM - what reserouces do you rely on to broaden your technical "toolkit"?

This is my version of the "T-Shaped marketer". It's how I coach PMMs to develop their skills. 

https://docs.google.com/presentation/d/1NhRmE4pf96M--bih_MSoT-7YpKW3p51i9_-yBhKhIZo/edit#slide=id.p

I think starting by developing a great generalist base of knowledge is key. From there getting good at a set of skills more particular to PMM (writing, sales enablement, market research, creativity, product knowleged, presenting, etc) Those are the things we should be really good at. 

Then finally there are few things unique to PMM , Positioning, product launches, Narrative design, cross-functional collaboration. Other teams do these but not like us. These are the things to get great at. It's likely these will always be a work in progress.