Ask HN: What is the best way to master GTM?

We are a team of two engineers and we get stuck in engineering, missing the trees instead of the forests. I would like to sharpen my GTM skills, and I would like to learn what works, what doesn't.

1. What should I go study? 2. Teams of technical founders how do you spend time between product & GTM?

I am considering marking some days as GTM days, so that it is at least top of mind for some days of the week.