Developing an art style surely is a tedious thing. It's a lot of trial and error from my own experience. How long did it take you to develop the style you have now? It took me a few months to develop my lineless style and even then I still haven't perfected it.
Well, I guess you could say that it's the same amount of time that passed since I started drawing, so almost a year
My style is still changing little by little, but the sort that you see these days took about 3 years to fully comprehend.
A few months, I think. When I started drawing again, the base of my current style was there but it needed some refinement to jump from doodles on paper to digital art. I messed around with trying to do lineart for a month or so but it just wasn't working for me. So I tried lineless! It took a while to work out how to define my shapes but after I had a look that I liked I went with it! It wasn't as clean as my current art but the bare bones of my current style was there.
oh boy... my style was first "made" when i was 13 and i had been binging a bunch of art videos for a fandom with bad art. so obviously i want cool art like that too!! and so the style was made and it was pretty awful.. so timeskip to sometime in 2015?? 2016?? i dont know??? anyways the first major change was with the eyes and maybe the anatomy (but it still wasnt good lmao) and i guess slowly other things changed with it..... my art was pretty garbage for 2-3 years because i didnt want to do anything cool with it haha the first "big" development was when i deiced to make an "alt style" for fun while incorporated fluffy hair, big round eyes, hearts in the eyes to replace a shine, and chubbier limbs. (at the time my characters limbs were stick thin!) sound kinda familiar? eventually this alt style blended with my current one at the time and now to be honest my current stuff resembles the alt style more!! other bigger developments happened when i made the faces rounder (giving it that soft look), i made an inking mistake on the nose (which led to the heart noses, which seems to be a huge trademark of my stuff according to you guys!), and just generally studying from others to fix my anatomy. over 2018 my style is pretty consistent but im really happy with where it is now!! so tldr: its been developing for like 4-5 years and most of the big developments were brought on my mistakes