Let's start with three of the easiest.
Mining
Requires: No other skills
Tools: mining pick, smelting tongs
This craft is the easiest, it should only take you 1 hour to GM. Possibly an hour and a half. You should probably buy a mining pick at a provisioner's, since it would be hard to craft a mining pick without mining first!*
Use the mining pick on a mountain range to mine. If you don't strike ore the first time, move on. You don't have to smelt your ores yet, but you'll need to use smelting tongs on a brazier (the big fire pit) to get ingots for other crafts.
Just keep mining. Then go empty your inventory, and mine some more. Save all the jewels and exotic ores you get, as you'll need them later. Make sure you raise this to get raw blackrock, gold nuggets, copper, silver, zinc, etc, and save them for use in other crafting. Literally, there are no special instructions, or secrets.
Just mine, and you'll GM this craft. Shift + F9 is your friend. That was an easy first craft to GM!
If you have a flying carpet (a special event item) or you pay for a Drake mount, you can fly over mountain ranges to mine them. Extremely useful!
*Madman Mode: Deconstruct found items to raise Tinkering to 10, and craft a mining pick!
Alchemy
Requires: No other skills, but recommend some Mining.
Tools: alembic, flask, vial, reinforced flask
Please note: You can GM Alchemy straight through by crafting the various yellow potions. You never
have to craft anything else. However, you will benefit later from doing some other crafting now. I recommend raising many crafts at once. It is more efficient to craft Venomous Logs, Dragonscales, Dark Thread, and Essences, now.
This craft is important, and pretty easy to GM. Not only do we all use mega yellows, but Alchemy will support other crafts (like Enchanting, Woodcrafting, Tailoring, Weaponsmith, and Armourer).
You can begin alchemy in a number of ways. You can use an mortar and pestle on carapaces from bug swarms. You can get spores from a diseased bandage by using a Sieve (55 Tinkering, Weaponsmith/Armourer 20).
Flasks, Ginseng, Spiders' Silk, Blood Moss, and all of the materials you'll need to grind out GM, are available in Apothecary. You can gather the materials by hunting, and craft Flasks (70 Tinkering). You can get reinforced flasks (80 Tinkering) by crafting, but that's the hard way. I'd suggest just buying or trading for mega yellows and saving the flasks.
Once you get into 40-50 range, go ahead and craft venomous logs. Use fountains to get bunches of fangs, then make snake's venom (45). Oddly enough, venomous logs only require 40 Alchemy. You will make good use of about 50 or so venomous logs when you go for woodcrafting. Then, you can jump to refined yellow potions (easy).
Next, make Dragon scales. They help process raw blackrock. You'll need a Dragonscale Saw (85 Tinkering, 35 Weaponsmith/Armourer, 80 Mining). Blackrock can be used to make dark thread, which will help with Tailoring. If you're still not to 65 Alchemy, make yellows as needed.
Now, process raw blackrock and make Dark thread. Do this to raise your skills. This will help with Tailoring later.
Now we should be ready to make essences - these are going to be much needed to GM Enchanting. They'll also raise your skill pretty high. Hydra fangs, Minotaur hearts, and Glowing embers. Vials are buyable (and craftable, at 75 Tinkering). Once you make hundreds of the essences, you should have at least 85 Alchemy, and you'll be ready for Enchanting later.
At this point, just Mega Yellow your way to GM. If you run out of reinforced flasks, you can craft them (80 Tinkering, 35 Weaponsmith/Armourer, 60 Mining), buy them, or even offer a trade ("1 mega yellow pot for 1 empty reinforced flask, up to 100!"). You'll drink them all eventually! Congratulations, you've GMed Alchemy.
Tinkering
Requires: Mining, Woodcrafting
Tools: tinker's toolkit, wand of deconstruction
Tinkering is astonishingly easy to GM if you have wands of deconstruction. It's redonkadonk easy. You'll build some other skills along the way too.
All you need to GM tinkering are: poles, ingots, and raw glass. Bing bang boom, that's it. You'll probably want some gold nuggets too, since that will help with Enchanting later.
Poles you get from Woodcrafting (5). Ingots and gold nuggets you get from Mining (any skill level). Raw glass you get from deconstructing, which we'll discuss later.
Start with poles. Make fishing rods until you can make jars. Then, get some raw glass and make jars. You can farm sand traps, or decon flasks, for the raw glass. Scissors are great to raise your skill to 30. And now, the gold nuggets: Make a bazillion rings. You'll use them for enchanting later. Make 'em till they stop raising your skill.
At this point, superior fishing rods (again just the pole) will get you high enough to make studs out of ingots. Make studs! Make studs until you can make nails, and then switch to nails - they'll come in handy later for Woodcrafting. Make nails on nails until they don't raise your skill anymore. Now it's time for the raw glass, baby.
Raw glass, you get from buying flasks and deconstructing them. I ended up buying around 3000 flasks to GM tinkering, all without spending a single second searching for supplies. Decon them, and make them into flasks
Then make them into vials. Then decon some reinforced flasks and remake them, if you want your skill to rise a bit faster. You can also craft the silver sheets (35 Weaponsmith/Armourer, 60 Mining). Once you get 90 from flasks, vials, and reinforced flasks, you're home free. Make mirrors out of glass you get from decon, until you have 100% tinkering. Congrats. Easy peasy!