This is great! You are able to render different parts of the portrait so you can tell what they are (I love the dress specifically)
As for rendering, is there a particular artist/s that inspire you? Perhaps they have YouTube videos or tips on how to acquire the render/style you are looking for!
Other than that studies are always a great way to practice rendering realistically, try going on Pinterest and find a decent portrait photo with good lighting and try to replicate it, try to understand how something is rendered and pay attention how the environment/lighting is affecting the subject.
If you'd like any suggestions on painting YouTube's like sinix, rossdraws, paintable are great artists who have helped me in finding different way to render people, I hope this helps and best of luck!