I learned the hard way that I could not create a good (detailed) model of a
skyscraper without a very detailed design. The Empire State and Chrysler
buildings have features lit up by flood lights on their exterior. You can't
simulate that effect with windows. I started out making a prototype of the
Empire and it turned out awful (see pic right).
So I created a detailed design in Autocad and then printed out the design on
11x17 paper at full-scale. I could then cut out the various pieces of the
Empire State from the paper and use them as stencils on the wood. Use
1/32" tolerances on everything for a much better fit. 1/16" turns out
sloppy.
Because of limited room in my skyscapers, I cut holes in the back
support and inserted the xmas lights deep into these holes. I used
particle board because I could cut holes for xmas lights much closer
together in particle board whereas plywood would just splinter apart.
Each skyscraper probably won't need a whole 50 or 100 lights, so if you
take lights out of the strand, you'll need to insert a resistor so that
the remaining lights don't burn brighter and burn out quickly. I've
found that a string of 50 lights usually consumes about 10 Watts, so
since I only needed 23 lights on the Empire State building, I removed
the unneeded lights and inserted a 5 Watt 127 Ohm resistor.