Only use coupons for magatamas, refining, and mood scrolls.

I think you need to prioritize based on your current needs.

Once I get around lvl 3ish magatamas on my ninjas, I focus on refining and a bit on mood scrolls.

Imho, I would prioritize on magatamas, refining, then mood scrolls.
In my experience, I've spent most of my coupons on magatamas and refining. Mood scrolls are a bit new atm, so I'm only spending a little bit on it.

Also, refining is extremely expensive so make sure to spend your coupons at your own discretion.
This post was last edited by Godsu* at 2016-8-20 09:41

Magatamas were priority for me because they were the only thing worthwhile to purchase with coupons before I hit lvl 40+, so naturally I invested the majority of my coupons on those shiny jades.

Refining is great but can be extremely expensive like I mentioned, so I would only buy enough to secure at least lvl 1 refining on your main toons that need them.

Regarding which lvl magatamas to get, I would only buy lvl 2's and lvl them as you go from the random maga drops from instances - lvl 4's are way too expensive.

No idea about future clothes and what not.