Hey Masu! Thank you! I'm glad to know that you liked it. This time I used more bright colors because I wanted to do a test.
The details of the tail, I started it manually, then I copied some layers and helped myself with a brush, since making pretty lines is a bit difficult for me (That's why I could never use a lineart..), because my tablet It has no screen, although I admit that now I do my lines better than when I started using it a year ago.
In previous sirens I have done them without brushes, it takes a long time but it is also effective.