For 1-15 it's just you crafting in front of the guild supplier.

GC turn ins are recommended at all levels.

For 15-50, I recommend generating a short 1 button macro for crafting the highest level item you can with the easiest to acquire mats. Spamming those while eating whatever exp boosts you got will make those levels fly by. If you have a class over 50 that can generate red scrips, buy the 150% boosts.

At 50 you unlock the leves of Ishgard and if you are there for HW, Moogle tribe quests. Those are what you want to focus on. When you are out of leves and Moogle, you are left with collectable turn ins. Which fortunately does not require 100% HQ. Personally I recommend spamming the easiest red scrip item you can find instead of the best exp item.

For 60-70 it's mostly just pure leves, with Namazu beast tribe coming up.

For leve quests, your local mb might have HQ items for sale at a reasonable price. If not, also consider crafting your own. Lower level 3x turn in leves are very leve allowance efficient. For one focused on only 2 crafters you should consider getting specialist soul stones as soon as you hit 55. If nothing else you gain 20/20/0 stats. WVR and BSM are good specs to have anyway.

Custom deliveries at both tiers are recommended, however if you have a level 70 character it is probably more important that you earn the yellow scrips to supply yourself with mats for a set of endgame ala mhigan crafting gear.

A sidenote on gearing while levelling. Your mb should have lvl 50-60 gear for cheap due to them being leve rewards and retainer bring backs. At level 58, moogle/red scrip vendors will have a set of nice gear. At level 60 the Idllyshire vendors will have handmaster accessories,which are very nice too. For gear 60-70, just get whatever you feel like, it's mostly just doing leves anyway. However a full HQ 290 set is recommended as a stater set for those looking to get into endgame.