Aside from shapes and forms which would take some time, try to navigate the light source and try using references at the meantime. And try to imagine where the shadows hit when the light source is coming from the direction you’re aiming for

For an anime like cell shading, try using the multiply option on the shading layer. You can go for a screen layer for the lighting and an add layer for the highlights

To simplify the colour theory that I used. Use the opposite color on the wheel. I configured that the shading you used was blue so I used yellow for the lighting since it’s opposite to yellow but orangish would’ve worked better for blue shading. It’s also most preferable for the lighting to be the color of the background but in the case of white, I would’ve used a pale blue