First, do everything necessary to prepare a surface for the paint. That includes more than simple scraping. It means getting the wood back to it’s natural beauty.
Next, use the right highest quality painting products.
Finally, apply the paint the old school way, meaning mad skills with a paintbrush and roller.
Mad skills also require mad passion for the gig. That is the defining factor between a good paint job and a great one. Quality and passion.
I may not be painting the Sistine chapel (at the moment) but I bring all the passion my Italian predecessor did to every one of my projects.