I was talking about this with some folks and was asked to post the process I went through here. This info is based on what was available to us in patch 2.38. Below is the process, and in the middle is essentially a side-post regarding the melding of your gear.
1. Grats on reaching level 50!
You can gather most basic stuff now, but with unspoiled nodes and big fish out there, you need to do a bit more work if you want to take your gatherers to the max. At this point, decide how you want to proceed. You may want to focus on just 1 of the 3 classes and leave the rest behind, or go for topping off 2 or 3 of the classes. Either way the process is the same, you just need to account for multiple classes.
2. Gear up!
You will want to pursue the il55 gear for your class(es), and ideally get the accessories from the master craft recipes. If you have advanced crafting classes it'll be possible to make most or all of the gear yourself, otherwise gather up the expensive materials and get a buddy to craft, or just buy the gear. It's expensive to buy, and just a time investment on gathering to make stuff yourself, or get someone else to make stuff.
3. Materia time!
Those stats may look nice but they aren't enough to try for higher 1 star items. You need to boost your stats with materia. Get yourself a small stack of grade 4 carb matter, medium stack of grade 3, and full stacks of grade 2 and 1. You will need all 4 grades of materia too. Below is the general idea for materia. Even though we're working toward gathering materia, the most efficient way to bond gear to 100% and convert to materia is to equip several pieces of gathering gear, use several of your best combat gear pieces, and go kill stuff.
Grade 3 and 4
The best bet here is to make/buy il45-47 gathering gear, and go fight lv 49-50 enemies. I typically go with 6 pieces, trying not to interfere with my best combat item slots. If you're going solo any beast lair or castrum will do. For the quickest turn-around join a party in Urth's Gift, where you'll be changing gear every 15-20 min. Solo plan on 40-45 min. There is roughly a 10% chance of getting grade 4 materia, otherwise you get grade 3.
The Urth's approach will work well again if you use items that are above il37, but if using il31-36 you'll do better fighting lower enemies (say lv 42-45) in any of the beast lairs. Again go with 6-8 slots of gear to bond so you can kill at a decent pace, which should be 10 min (party in urth's) to 15 min (solo).
In the time vs money vs return realm, just go to any of the cities and buy the il5-10 gathering armors and jewelry. Go ahead and get full sets even, as your weapon alone will be strong enough. Then, go somewhere that has a high density of lv 16-18 enemies, like east shroud. This gear will bond in 5 min or less.
On a positive note, you won't need many grade 4 materias. You will need many grade 1 and 2 though, to be illustrated later.
4. Melding time!
Start out with the bits that are common to all gathering classes, especially if you are wanting to gear up multiple classes. The following melds will max out your stats for the given slots. The order below is minimal risk for high materia, and high risk for low materia.
dodore belt: GP IV, Gathering II, Perception I ... or GP III, Gathering II, Perception I, GP I.
dodore choker: GP IV, Gathering II, Perception II, GP II, GP II
rose gold earrings of gathering: GP IV, Gathering II, Perception II, GP II, GP II
militia bracelets: GP IV, GP III, GP III, Gathering II, Perception II
dodore ring: GP IV, Gathering II, Perception I ... or GP III, Gathering II, Perception I, GP I
As you can see the accessories are heavy on GP. If you don't want to go for all that GP IV materia then I suggest using them on the bracelets first, then neck or earrings, lastly belt or rings. Also, when you see the same grade materia in back to back melds you can swap order based on your supply. As you see I always put GP after Gathering and Perception in the overmelds (which is the 2nd-5th materia in each item) as GP will be the least important of the 3 stats (you will very easily exceed 600). Personally I skipped the GP IV materia in the neck and earrings.
When done with these melds, your miner/botanist will look like this: http://ffxiv.ariyala.com/NXQN
... and fisher: http://ffxiv.ariyala.com/NXQP
Note: to advance you don't have to complete those last GP overmelds now, most important thing is getting all the gathering and perception done.
5. ... more melding!
You've got your common-to-all classes pieces set, but still don't have enough stats to gather on higher 1-star nodes yet. This means melding your class-specific items. The melds are listed below for each slot, and of course with fisher you can ignore any GP melds since those mean nothing to fisher.
chest: Gathering IV, Perception IV, Gathering III, GP I
gloves: Gathering III, Perception II, Gathering I, GP I
legs: Gathering IV, GP III, Perception I, GP I
feet: Percpetion IV, GP III, Gathering I, GP I
With any of these items, you can opt to skip an IV materia and use 2 lower grades, since I didn't touch the 5th slot with any of these melds. Again for fisher cut out the GP entirely.
With these melds completed, you now have enough stats to move on to higher gathering!
6. Forager hat and tools!
There is a NPC in Mor Dhona where you are able to exchange items for the Forager hat and tools. I suggest going for the hat first, and later the tool.
Umbral Rocks can be harvested at 6am in South Shroud, near Camp Tranquil
Redolent Logs can be harvested at 2am in South Shroud, north of Camp Tranquil
Silver Sovereigns can be fished up in Lower La Noscea, atop that cliff south of town. GSM can make the lure (which thankfully you very rarely lose), and it's best to attempt fishing outside of the mahi-mahi time window.
All of the above are a time sink, just keep working at it and eventually you'll get enough to trade for the hat (only need 1 hat, all 3 classes can use it) and finally the tool.
When completed, you will have enough gathering and perception to raid the 2 star miner and botanist nodes, and get working on big fishing (prepare for a lot of frustration though!). Regarding miner and botanist, here is a concise reference for what is available from their nodes, and the stat requirements. http://ffxiv.ariyala.com/Gathering
7. Supra tools?
This will be a big step, especially if you don't have a well leveled LTW, BSM, and CRP. You absolutely need the max melds from steps 4 and 5 above as a minimum.
Each supra tool requires 10 fieldcraft demimateria 3 (need LTW desynth 80+), 3 mastercraft demimateria (BSM desynth 80+, CRP able to easily make 2-star token turn-ins for artisan saws), and some specified gathered item. BTN/MIN require 99 NQ items from an unspoiled node, and FSH needs 3 NQ or 2 HQ fish that are a royal pain to catch. If you're able to do the demimaterias yourself, it's a big time sink with some cash investment. Buying the materias is a big cash investment. The gathered items (as of 2.55) require 408 gathering for BTN/MIN, and 349 for FSH.
BTN logs are on the east side of central shroud at 6am
MIN rocks are on the northeast side of central thanalan at 2am
FSH, look up olgoi (should be good enough to find a page)
8. Lucis tools?
This is the final installment for the 2.x series. BTN/MIN require 99 of the HQ versions of the supra turn-ins, which will require 389 perception. You're at the mercy of RNG though as your best bet in gathering these items is to make all nodes visible (300 GP) and then add 30% to HQ chance (300 GP). You won't have 100% gathering chance here so that's a 2nd layer of RNG to deal with.
I don't know the details of FSH yet, that will come later.
Beyond the gathered items, each lucis requires 20 moonstones, and 60 of another specified item. Moonstones can come from toadskin and up maps, but this isn't very reliable. The most reliable way to get them are by spending 4000 GC seals per. At 80k per set of 20, go do your favorite GC seal collection activity. The 60 of the other item can be bought at 600 seals per (so 36k total) and also the leves in St Coinach's randomly offer the items as awards.
Luckily this step isn't really difficult, it's just a huge time sink. If you can get your hands on forager body gear and secondary tools, those will increase your gathering chances some, but are not required to get this step done. I think you will have to add a materia or 2 to your off-hand tool though to reach the needed stats if you don't have any of this forager gear though.