Level Pacing?

[Roth_Trailfinder]

With the level 15 cross class skills, and level-appropriate HQ gear (no need for melding), you can fairly reliably HQ any 70 or 80 durability recipe starting in the lower-mid 20's. 40 Durability recipes will be harder and may take some HQ materials.

With this in mind, you are giving up exp per leve allowance by having someone else craft your hand ins. Your call, spend some time crafting (with a decent, though less-than-certain, chance at HQ) or bug someone to make them for you for less exp.

Manuals, I did not try the ones from ARR. The ones you get for HW, I found, I simply could not craft fast enough unless I was using Quick Synthesis. At that point (Birch Syrup from Culinarian, I'm looking at you) the manual offered enough exp/time to make it faster leveling than crafting a bunch of 100% items.

As for the DoL jobs, for Mining and Botany do Leves. Those will go through 50. After 50, if your gear is good enough (and you have 600 GP, through some combination of melding and food) start doing Collectibles, especially the 10, 12, and 2 oclock ones. For Fishing, I found that I got levels at a decent enough clip just fishing, without paying any attention at all to leves or Collectibles. That was 1-60.

[TallonOverworld]

Miner:

Leves! Bread and butter of your way to 60 imo. I hardly did any collectibles from 50-60 or bothered with the gathering log. Unfortunately we can't buy the items required for leves from the market and just turn them in so each leve must be done completely. Personally i used the squadron gathering manual as a tool for more xp from ~40lvl on + gathering food. I don't think its much of a help to use manuals before that level as the bonus is not that sufficient.
Some bit of guide now for your leves: Always complete them with the safest difficulty. Believe me, going way above the recommended difficulty will result in earning low xp or sometimes fail it completely so do them according to the gathering percentage and not rely on luck.

Currently there are 3 types of leves for miner and botanist, evaluation, minimum amount and simple gathering. In the evaluation leves you are asked to gather 2 items (one easy, one more difficult) from each node and on success you earn points. When you reach specific amount of points you earn bonus xp up to a maximum of 25%. You should manage to reach the maximum points even if that means to use all your GP for it. I won't be analyzing the other 2 types as they are pretty straightforward and much easier.

Fisher:

My first gathering class. From what i remember i used leves here to level up and in many cases i bought what was required from the market (provided they were cheap and i could afford the gil) and rarely did any fishing. What matters most for fisher is hq fish as the bonus xp earned can be 100% or maybe more. I for one, did collectibles from 50-60 and they helped me a lot to be honest so i would suggest you do them as well. Now regarding leves they are all easy but there is a catch.
Some leves require you to fish and turn in 3 fish to complete it, but afterwards the npc asks for 6 more (3+3). Of course this is optional but i can't describe its usefulness. Its like doing 3 leves in 1 and not to mention if you turn in 9 hq fishes. The bonus xp is MASSIVE. In such cases, all i did was just find all the fish required for the respective level leves and then sit for hours on the fishing spots to fish them. In the end, i got myself +2 levels or more.
Comparing to miner, fisher was much more easy to level for me so i would recommend that you start with it.

Well this was how i did it. You can experiment yourself to find out which way works best for you but i got the best results with what is mentioned above. Unfortunately, i don't have any crafted class atm so i can't help you with that.