I have always just followed my nose so to speak. Each year or over time I tend to find new things -- some I follow up on others I store for later. Every year or over time I lose interest in some things or even grow to abhor them. I read the tech threads here and elsewhere to keep my mind focused on the less thrilling, but peer to the thrilling aspects. The thrilling parts, the parts that relate to the message and the final image is fed by all things not photographic and seldom artistic. All in all, each year (or over time) I tend to get 'better' -- like overcoming a mental disorder.
As for focal lengths -- wide for things needing to be big, long for things requiring intimacy. When both are required I go into convulsions.
Happy new year.