Still-life painting on iPad(reference attached)

Hi Matt,

I finished this work in 3 hours a few weeks ago, and I want to use it as an example to ask a question which has haunted me for long.

I am not quite into hyperrealism yet still I would like to achieve a smooth transition.  However, it has been an obstacle for me. You can tell from the application of hatching there, that I almost used brushes as pencils. I just cannot merge those colors naturally. According to the information I have gleaned, the crux seems to be the subtle values.

I want to ask for your advice to work on the smooth transition. Is it a hand-eye coordination thing that will be solved as time passes, or should I regularly spend a load of time on drawing/painting as detailed as I can, or anything else?

Thanks for your time.

Amber(Kexin, Wang)