To all of the people here who have achieved things like top 100 or top 10 In events : How?

I've been planning to try and tier for the HHW second band story event when it comes around, and I'd really like to be prepared for it. How many Live Boost items should I stock up on? How many stars? Would a three star that's booth on-attribute and on-character be more worth my team than a four star that's only on-attribute?

Any and all help would be super appreciated!