It's better to be decent in a lot of areas than to be great in one area and terrible in another. If A, B, C, D is how much value you provide in different areas, you should try to maximize ln(A)+ln(B)+ln(C)+ln(D) rather than A+B+C+D. Also see "Law of diminishing returns", "All happy families are alike; each unhappy family is unhappy in its own way."

In creative fields nobody knows what they're doing and most time and money is wasted. It's often as important to think about what thing to do as doing the thing. You will most likely provide great value to your company/work a few days of the year (the days where you implement some feature your customer really needs or where you fix some potential or ongoing big production problem) and most days you will provide break-even or negative value. Also see "Impostor syndrome".

Always automate manual or boring processes. Do not think too much about ROI calculations, they don't work because productivity in creative fields is very non-linear. Instant feedback is very important for concentration and morale.

If you're prone to anxiety, saving money and building skills allows you to act without fear of major setbacks. And most of the time it's better to ask for forgiveness than permission.