You know I've noticed something similar- If I use ultra fines or always grab fresh markers the lines are finer and sharper giving more room for detail- but the trade off is it takes more time to complete something in that manner. I have an Etsy account, but with so many people/artist pouring their stuff onto the site, its just a bit much i think. Maybe I'll have another go at it tho.
I make something new everyday- no matter what. Doesnt have to be huge, doesn't have to top the last one, but something enough to where i can feel accomplished for the day and had some practice. As long as you're not trying to create wall sized masterpieces daily, I'm sure you'll do great at
just takes a little bit of discipline