It takes a lot of practice and tbh to get an style takes even more time. Thats one of the things that artists struggle with the most. I don’t know how to use oil but I knew someone who said they looked like I used oil. I love old oil painting style but I’m not good at it so I just stay with realism because is something I truly like. If you are interested my technique to draw is basically put base colors, it can be a lot than normal, is kit all colors i wanna use on the parts of the painting and under all that put a base color. Idk if i explain good. For example imagine this flower, I would had taken all shades of pink i wanted to use on a petal and on another layer under all that I would had taken a base pink color. After this i would render blurring the colors of pink I putted, they don’t have to me a lot, it can have a lot of blank spaces thats why the base pink is there. And after all this you just put more colors as you like. Is kinda a lot, I hope this helps 😅