I've done a lot of gathering lately to get Blue Gatherer's Scrip so I could get the gathering Folklore tomes you need to collect Seventh Heavens and Astral Moraines. Here's what I've found.
There is a WEALTH of information available in this Reddit post: https://www.reddit.com/r/ffxiv/comments/3cy4q4/gathering_collectables_for_scrips_a_rotation_and/
Condensed Notes on Scrip Gathering
You don't need to have perfect gear to start gathering collectables, but 600 GP is the magic number to do the most effective rotations.
i180 Miner/Botanist/Fisher gear is available in Idyllshire, purchased with Rowena's Token (Blue Gatherer's Scrip) and Counterfoils that you purchase with Red Scrip collectables specific to each class. So gathering scrip gets easier as you go along.
Try to get just enough Collectability to qualify for the turn-in, it's better to have more collectables than one with maximum Collectability
Always eat GP food, NQ Dzemael Gratin can be cheaply bought in The Pillars in Ishgard and gives 24 GP.
For blue scrip, the best rotation needs 600 GP:
Discerning Eye > Methodical Appraisal > Discerning Eye > Methodical Appraisal > Single Mind > Methodical Apprisal, then Collecting the item.
For red scrip, I've used a couple of rotations, they both need 600 GP.
The first one was done with i145 mainhand/offhand, i180 left side gear and Level 50 melded accessories:
Discerning Eye > Methodical Appraisal > Discerning Eye > Methodical Appraisal > Utmost Care > Methodical Appraisal > Utmost Care > Methodical Appraisal
The second was done with i190 mainhand/offhand, i180 left side gear, and Level 50 melded accessories:
Discerning Eye > Impulsive Appraisal > Discerning Eye > Impulsive Appraisal > Discerning Eye > Methodical Appraisal
Here're the schedules I used when gathering for scrip: