i Trying To Make Buddha Head For
Leonardo 100k Buddha Head Request

Artist:Me
Size:512 x 512

CnC

Set the "index to n colors" option in gimp to "0" for HQ spinning globes.

Anyways, to give some comments on the head...

It seems like you only used 1 tool for making this head, which is the dodge/burn tool, which is pretty easy to notice, I would recommend you to use the path/pen tool to make straight lines and lower the opacity to make shadows or highlights.

His eyelids need to be darker, as does some other details.

To tell you the truth I would say it's pretty boring since it's all gray :/

I Only Use Smudge And Airbrush Tool

I still recommend you to use the pen tool ,as there is a lot of uneven lines on there.

Not to like it, but the Shading was great..
The eye, its hard to look.. so add more detail there..
The Ear is in a Right place, and looks realistic..
the Mouth isnt look nice, its look like waves, or etc like that..
Chin, are cool.. Nice shade there too..
Not to good, but can be more .. 7/10

or he can keep practising with his mouse work.
pen tool gives a specific look, which he may not necesarilly want.