こんにちは。
髪の塗りは良い感じだと思います。

気になった所としては、キャラの色や髪形が大分違うので、よく観察して合わせてみてください。
その他は画像にまとめましたので、ご覧いただければと。

いいねをつけたくなるよな見る人を楽しませる評価される絵とのことですが、答えは簡単で、既に評価されている上手いイラストは沢山あるのでそちらを参考にしていきましょう。
その時にただ「上手いなぁ」と眺めるのではなく、どこが上手いのかどこが惹きつけられるのかを言語化してご自身のイラストに取り入れていってみてください。
ご参考になれば幸いです。

People lead unique lives and live with diverse values.
Therefore, the favorite picture will also be 100 people 100 different.

For me, a painting that attracts the viewer is a painting that touches the heartstrings.
Longing, admiration, affection, respect, attachment, sadness, anger, and various other emotions sometimes torment us, sometimes give us peace, and sometimes bring us happiness.

If there is an affinity between the ``emotions striking in the artist's heart (sometimes intense, and other times pleasant)'' and the ``expression of a painting'', it resonates with the viewer's heart and revives emotions.
The common point of paintings that move the viewer regardless of the type of emotion is the emotion of the artist.

Based on the discussion above.

It is important that the painter himself is immersed in the feeling that the viewer will enjoy, in order to create a "picture that can be enjoyed."

If you draw a picture with ruby as a subject that attracts the viewer, I recommend that you reflect on and organize your thoughts on ruby.
What should I do with the “character and charm of ruby” that created that feeling?
more accurately
more accurately
stronger
more concentrated
Is it possible to put it in a picture?
For example, if the relationship with Aqua is important, there may be developments such as placing Aqua itself or a symbol that suggests it as an element on the screen.

In order to enjoy drawing, let's fully enjoy introspection before holding a paintbrush.

Have a fulfilling drawing life.