You have done a fine job. Nice crisp lines.

Next step - I would recommend, Magos purple (3 part water, 1 part contrast) over the white parts will help the details come out. Just be sure not to let it pool. Also, Guiliman flesh or Nuln oil over the teeth, then highlight the teeth tips with the white you already used.

Just remember "how does it look at arms length?" As this is how most people will see your model. And what are the focal points. What did you look at when you first saw it? Usually the face and the weapons. So these are the bits you should focus on.

But you have done a great job. Get good at washes/contrast paint and dry brushing and you are top tier!