Just the other day I watched this clip from Photoshop tutorials.
It creates a half sketch effect and you learn things like masks, creating clipping masks, blending moded and how to install new brushes.
It's a great (and easy) tutorial! Don't be afraid to give it a go.
This is what I made of it: here's the start situation.
And this is my end result.
And have you already discovered our Facebook page Humans of the Nordic Region?
picture from Pixabay.com