Collectables and Perception

[PROBOUND]

I see, my gain on radiant moraines increased to 172 too, which was lesser before

is there any usefull strategy to hit 8/8 with max perc or is it just luck based?
I can get 7/8 nearly everytime, but theres still something missing for 8/8

Which methods is best used to get 7/8 everytime? I'm assuming this is only 1 item?