thank you for the feed back,
it just happened that I feel to draw a tree at 1am, so why not :D. just do it and finished it (well, its not good enough tho)

yeah, actually I feel the leaves feel like a paper art, I still wondering how to convey the leaf feeling

thanks again for the constructive feedback
 

Hey there, welcome!

You're a hardcore guy, starting with a tree ;)

I'm happy you controlled your colors and used dithering (your shading technique's name).

-The colors contrast too much from top to bottom: the leafing on the down sides should still be brighter.

- To represent leaves in pixel art (not every single one of course) we use small shapes (feel free to observe around the website ;)

The shading of the trunk is very good though, and your colors are well chosen.

Well I hope this helped ;)

Of course I don't expect you to master everything on your first piece and this is very good for a first PA, so I hope you'll enjoy your stay here and get to upgrade your skills and have fun ;)