Whenever I have extra time I go to one of these sites to bone up on specific photoshop / dimension / illustrator tutorials on Youtube. I almost always come away with a new trick, technique, or application.
Photoshop Training Channel - Jesus Ramirez
PixImperfect - Unmesh Dinda
Both guys really know their stuff.
I am familiar with PixImperfect. Good channel. I’ll check out the PTC channel. Thanks.
Maybe it is not tutorials, but I find this channels very helpful with my graphic design job: The Futur, Charli Marie, Yes I’m a Designer, Dan Gartman, Will Paterson, Matt Borchert, Pickel & Bracket, Gigantic…
For beginners, there are few good tutorials on this link
If you’re interested in learning how to start with isometric design, you can check this tutorial. I find it quite challenging to find a good isometric tutorial that explains step by step all the process.