Writing - especially this course:

https://www.coursera.org/learn/sciwrite

and this book:

https://www.amazon.co.uk/Philosophical-Writing-Introduction-P-Martinich/dp/1119010039

Forecasting:
Metaculus intro resources, partially complete introductory video series, book.

A few "soft" or somewhat meta suggestions:

• Learning how to learn. 
• Getting things done. There are a variety of online courses, I haven't taken any and so can't recommend them but I do recommend skimming the OG book and taking time to implement its recommendations wholeheartedly to see if it works for you.  Summary of the general approach here. 
• Negotiation. See also Getting to Yes. 

Critical thinking about research, including what biases are most common, why they apply, and how to know if an intervention works: https://training.cochrane.org/handbook https://training.cochrane.org/online-learning