Since I began tu publish my webcomics, i have been more comfortable using grays for the shadows.
I tried at the begining with screentones, but i did not feel satisfied with the results. After a time, i took it more like a part of my own process of doing manga.
Here is a pannel of the last page done of my story "Angel Guardian". If you want to take a look at it you can read it here
Which type of shadows would you prefer in the comics you read online?
Agramon after his encounter con Donoiel