My experience with 65-66 and 69 hood installs; This is mostly a dry fit, adjust and fit again procedure with no real short cuts that I know of. Yes, I usually start with the hood hinges firmly installed on the aprons. Best guess for location and install the hood.
!. Get some help at least two other people for each side
2. One person, you, giving directions; right, left, front, back.
3. Towels or protective pads mostly get in the way so don't bother.
4. The hood latch is not necessary at this point and install it later after you are satisfied with the hood fit.
5. Go slow and be careful
Brian