It is important that they are positioned accurately and well fixed. Firstly, decide where you are going to position each handle to maintain symmetry around your kitchen.
Then make a plywood template to mark the fixing positions on to the front of each door and drawer front.
Drill through the door or drawer using a fine drill i.e. less than 2.5mm you can then drill back from the rear face of your door or drawer using a 4.5mm drill.
By drilling twice you eliminate the chance of breaking out the door surface and help the accuracy of the holes positioned ready for handle fixing.