To make the large stars with middle cut out, I used two stars at the same time and placed some washi tape to keep the distance between the outside and inside star consistent across all the cuts. The inside star is two "steps" smaller than the outside star (so I didn't used the next size down from the outside star, but the next next star).
When it came to sticking them together, I decided to use up some retired Sticky Strip I still had laying around. Sticky Strip was great stuff, gave a very strong "stick". The backing of it was a bit of a pain, it was static-y and liked to stay on you even after a few vigorous flicks of the hand. With these stars being in a sunny spot I wanted an adhesive that would really hold on even when it got a bit warm.
I kept the distance between stars in the chain basically the same, though in hindsight varying them so neighbouring stars fit in the gaps better might have been the go. Probably one of those things that would only bother me though!
The stars were quite a hit, and I have to say I was really impressed with how they looked once hung, moving around and catching the light. They also happen to be placed opposite the Christmas tree, so at night time also catch the light off that and look even more fantastic.
Built for Free Using: My Stampin Blog