Nice job. It's always good to do practice! Here are my opinions about your work. Please remember they are just opinions so I'm not trying to put you down in any way :)
For the first form in the upper left: The shadow around the inner sphere is just a tad too wide making it seem to be pushed inwards a bit.
The form in the upper right is very well done!
Lower left form has a tad too bright value around the smaller ball, but generally looks really good.
And on the last one: I think the reflection on the upper right ball is bit too far away from the lower. Very nice work painting it there though!
Thanks, I appreciate your comments. :)
Nice job. It's always good to do practice! Here are my opinions about your work. Please remember they are just opinions so I'm not trying to put you down in any way :)
For the first form in the upper left: The shadow around the inner sphere is just a tad too wide making it seem to be pushed inwards a bit.
The form in the upper right is very well done!
Lower left form has a tad too bright value around the smaller ball, but generally looks really good.
And on the last one: I think the reflection on the upper right ball is bit too far away from the lower. Very nice work painting it there though!
I think these are quite well done :)