Get a still life photo workshop type book, and work your way through it.

Nothing will build more skill at carefully reading the light and attuning your eye to it's nuances of shape and shadow as they record on film.

With still life the output of an image is wholly the photographers responsibility.

If you want to see what is posible with natural light and plain backgrounds, look up 'Disfarmer' , a midwest US turn of the centrury photographer.