Seriously, how...

[vigioX-Sun]

they way to go for me was:
1-gathering up to 300 synt materials per class
2-create a nice rotation an make a macro
3-connect a second monitor to your PC
4-watch something in one screen,mute the game an hit the macros(in my case anime works fine)
5-wash an repeat

[Twilite]

If a person already has their crafts to 50 they could easily get to 60 in one day, two at most with leves. As for leves the regular ones are pretty infinite off of 99 could do like 2 jobs and then wait for them to replenish and do it again.

Takes about 17 days to from 0 to 99.

[Eul]

The fastest leve I find from all DoH job is Alchemist (From 56-60), because my server sold level 56 & 58 leve HQ item about same with HQ gil prize (Even gives profit too ).

[Katlyna]

TV + Macro + Make Bar... Make Bar... Make Bar for 15 days straight.

As Caimie said it took me around 160-200 leves. But 80% of the rest was just super hard core bar/cloth/leather/food grinding. Its INSANELY boring but very efficient since you get your money back (or you use the materials up). Note I attempted to HQ each getting the 300% XP bonus. But quick crafting would be faster XP grind at the cost of much more material consumed (and mostly only getting NQ results).

[wentouch]

I've raised every craft & gathering class to about 45 evenly across the board, solely by GC turn-ins daily since I began which was around the beginning of the year.

I'll craft whatever I couldn't purchase if it was reasonably simple. It lazy like that.

[Lemuria]

Hit lvl 56, start spamming blue scrip turn ins. Infinite allowances+the exp you get from crafting the turn ins.

Sadly, this is almost the single most inefficient means of leveling up as well. The average collectible hand-in is worth about 100k at level 56, with highest quality, you might squeeze out 120. The average levequest is also worth 120k, with a double bonus for HQ, making it 240k. The GC hand-ins, which can be done only once per day, can range from anywhere up to 1.6 million XP for a starred HQ hand-in.

So, yeah. While you can do tons of blue scrip hand-ins, you'd have to craft a significantly larger number of items to pull this off, so it's only for those who have a lot of gil or materials to throw away.

Note I attempted to HQ each getting the 300% XP bonus.

A minor correction, HQ hand-ins are worth double, not triple. This was reduced long before Heavensward was released, and the base experience for the leves increased at the same time to compensate.

[Roth_Trailfinder]

Leve hand ins are worth double if the NQ if you hand them in HQ.

When crafting something, you can get quadruple the base exp if you start with 0 Quality (IE - no HQ materials, only use NQ materials) and bring it to 100% HQ chance by maxing Quality. That is a 300% bonus to your crafting exp.

[CookieMonsta]

Sadly, this is almost the single most inefficient means of leveling up as well. The average collectible hand-in is worth about 100k at level 56, with highest quality, you might squeeze out 120. The average levequest is also worth 120k, with a double bonus for HQ, making it 240k. The GC hand-ins, which can be done only once per day, can range from anywhere up to 1.6 million XP for a starred HQ hand-in.

Blue Scrip turnins are not that bad. It depends on your timing.
The most efficient way to level 50-60 is to hone in on the cheapo recipes that appear in both the Leve and Rowena. Now, I understand not all classes have this equivalent but an example would be Mythrite Patas for BSM or Marron Glace for CUL. You craft/gather/buy a whole bunch of the raw mats. You then attempt to HQ every Pata, if you succeed in getting the HQ bar full then you turn off the collectible synthesis and let it HQ if you get part of the way then collect it for Rowena. This way, nothing is wasted.