There is doing the job and then there is doing the job right... I like to do things right, but it is OK to just do the job when it comes to enhancing kitchen cabinets... lightly sand everything to remove the airborne grease and impurities that have settled onto the cabinets and paint with a quality oil based paint... they will look clean and new in no time... I would however, remove the doors and hardware and do the hardware side separately... then rehang the doors to finish the front.