>>4116448Fanart is the easiest way to build a following, but it has it's pros and cons. The pros is that there is a higher chance to see audience engagement if the audience is familiar with the fandom (so the larger the fandom, the more engagement you'll have from the average joe). Depending on what you ultimately want to do, the con is that the more fan art you make, the less original work you have available to share. It can make it look like you have no ideas or self-driven concepts of your own, which can be detrimental to getting more professional commercial work.
Personal original work is next in line and is the most valuable in terms of helping you succeed professionally. This is where you can really let your own unique voice shine. For some artists, their style and content really resonates with people, and for others, not so much. Whether or not this type of work helps you build an engaged following is largely up to you and the type of work you make.
I find posting my commissioned work gets the least amount of engagement. I'm sure some people like seeing this stuff, but most people don't seem to give a fuck, unless it's exceptionally appealing work.
So overall, I'd really focus on your own personal work, with the occasional fanart to supplement it. If you're going to focus on one thing the most, I'd argue it should be personal work over fan art, even if it's harder at first. The artists that I see with the highest audience engagement are usually people who make personal work and not fan art.