These snowflakes are hard. I'm saying this as someone who is mildly proficient with an exacto blade from making models for set designs. I am grateful that the patterns are available for free, even if they were a more time consuming project than I originally thought.
I think my main problem was that I used paper that was too heavy. If you are going to make these, use a lightweight paper. I wanted to use a heavier paper so they wouldn't rip in storage, but that was not the right idea. I ended up breaking the tips off a few blades by trying to cut more than one layer at a time.
I skipped a few parts that just seemed insanely intricate, like the rebel insignia on the Y-Wing. I cut the T-47 Airspeeder off of the imperial walker snowflake because it just had to many little, tiny cuts. I did this to a few other snowflakes, too, and I think they turned out fine.
I was really sad that I accidentally cut the top off of my Star Destroyer, but I wasn't about to start over. That was the only big mistake I ended up making.
I think the patterns were well done overall, but could use a bit of simplification. I'd say this is a project for nerdy adults with long attention spans and a propensity for detail.