I am partial to Robert A Heinlein's 5 rules of writing. One of my writing heroes.
Put simply, get on with it, and stay focussed. This applies to pretty much any creative process. Writing, painting, software. You produce, make a few mistakes, fix them, learn, and move on
Going to have to work on a thick skin and learn to accept rejection.
Also need to cultivate the mindset that it is the journey which is important, You do not get an instant result. It is a marathon and not a sprint. As someone who used to do the sprint events and hated running more than 200m this could be a little tricky.