Share your event top tips please

I was following the advice on merge dragons wiki to beat events, but it hasn't worked in the last 2 for me and I've only completed 8/10 or 9/10. I also haven't been able to get all the prizes.

What are your best ways to smash the event and get all rewards? I saw some mention the prism flower method so they had loads of dragons, but I don't know what that is.

Thanks!