"The success of a student depends on his/her method of practice, 
moreso than the amount of time applied."

Here is a formula that can be followed:

Play through the composition a few times.  Get as much sight-reading practice from it as you can.

 

Allow yourself a section to conquer at a time.  Let us say, the first page.

 

Find the difficult spots and work them over until they become set.

 

Now play over the whole first page for continuity.  When this section is accomplished, use this same procedure on the next page or section.

 

If, after working through the entire composition, there remains a few difficult passages, pin-point your practice time solely to them. 

 

 

DO NOT WASTE TIME RUNNING THROUGH THE WHOLE COMPOSITION.
 

From the very beginning, read your music with memorizing in mind.  Constantly play as much as you can without the music.  Refer to it when you must.

 

Success depends on two items:

            (a) Intelligent practicing habits as described, plus
            (b) A generous amount of time