Going Goblin Mode

You can easily complete this in a day. Below is an optimized waypoint route, moving clockwise from Slam Central Station. These waypoints cover everything needed for the meta achievement, except Adventurer of Undermine, which requires killing 10 different rares. I recommend using a rare scanner addon to alert you when one spawns.

Before starting, I suggest completing the first four chapters of the Undermine storyline, as some items won’t be available until then.

For That Can-Do Attitude, you'll need to kick a can 25 times. You can kick the same can up to five times, though sometimes only three. To make this easier, set a keybind for 'Interact with Mouseover' and enable 'Show All' for Interact Key Icons. This will help you quickly spot cans and spam the keybind, potentially getting 3–5 kicks per can. If you reach a waypoint and don’t see a can, it was likely recently kicked by someone and has despawned. In that case, just continue with the list. If you're still short, check the achievement page—many players have shared additional can locations in the comments.

/way #2346 23.82 45.38 1 Nine-Tenths of the Law: Gorillion Fork
/way #2346 26.69 42.88 2 Treasures of Undermine: Unsupervised Takeout
/way #2346 40.40 28.51 3 Read Between the Lines: First Half of Noggenfogger's Journal (In the sewer on the floor in front of the third self on the right wall.)
/way #2346 40.84 21.27 4 Treasures of Undermine: Abandoned Toolbox
/way #2346 43.59 11.31 5 You're My Friend Now: On top of a dumpster
/way #2346 46.71 10.96 6 That Can-Do Attitude: Discarded Can
/way #2346 59.25 18.87 7 Treasures of Undermine: Lonely Tub (Use the fire extinguisher that is nearby.)
/way #2346 65.62 14.21 8 Read Between the Lines: Misplaced Work Order
/way #2346 69.65 21.64 9 Treasures of Undermine: Potent Potable
/way #2346 69.50 24.34 10 That Can-Do Attitude: Discarded Can (Usually two cans inside the dance area.)
/way #2346 75.14 22.95 11 Nine-Tenths of the Law: Gorillion Batteries (Go up the path at the right of the stage of the dance area.)
/way #2346 63.81 32.20 12 Treasures of Undermine: Marooned Floatmingo
/way #2346 65.86 43.95 13 You're My Friend Now: On the groud next to a fake palm tree
/way #2346 48.45 42.93 14 Treasures of Undermine: Unexploded Fireworks
/way #2346 43.64 51.55 15 Treasures of Undermine: Trick Deck of Cards (On the front desk.)
/way #2346 53.41 52.74 16 Treasures of Undermine: Uncracked Cold Ones
/way #2346 57.84 52.69 17 Treasures of Undermine: Fireworks Hat
/way #2346 56.67 55.47 18 Nine-Tenths of the Law: Gorillion Engine
/way #2346 58.58 59.32 19 Read Between the Lines: Gallywix's Notes
/way #2346 49.88 66.18 20 Treasures of Undermine: Suspicious Book
/way #2346 74.65 80.12 21 Treasures of Undermine: Papa's Prized Putter
/way #2346 71.45 85.94 22 Nine-Tenths of the Law: Gorillion Grease
/way #2346 65.26 88.26 23 You're My Friend Now: In a burrow
/way #2346 49.70 90.27 24 Treasures of Undermine: Exploded Plunger
/way #2346 42.28 82.31 25 Treasures of Undermine: Crumpled Schematics
/way #2346 40.50 89.09 26 That Can-Do Attitude: Discarded Can (Usually two cans here.)
/way #2346 35.95 85.63 27 You're My Friend Now: On the railing inside the building
/way #2346 34.33 82.86 28 Nine-Tenths of the Law: Gorillion Chasis
/way #2346 33.38 76.26 29 That Can-Do Attitude: Discarded Can
/way #2346 27.31 70.85 30 Read Between the Lines: A Threatening Letter
/way #2346 27.43 66.27 31 That Can-Do Attitude: Discarded Can
/way #2346 32.64 65.50 32 That Can-Do Attitude: Discarded Can
/way #2346 39.38 61.07 33 Treasures of Undermine: Particularly Nice Lamp
/way #2346 38.96 59.63 34 Treasures of Undermine: Blackened Dice
/way #2346 34.10 56.69 35 That Can-Do Attitude: Discarded Can
/way #2346 32.91 58.80 36 Read Between the Lines: Second Half of Noggenfogger's Journal
/way #2346 28.48 55.79 37 You're My Friend Now: Second floor on a trash can
/way #2346 24.40 56.20 38 That Can-Do Attitude: Discarded Can

After completing this list, you should only need two more items for the Read Between the Lines achievement. These can be found in the new subzones of The Ringing Deeps.

/way #2214 72.91 73.14 1 Read Between the Lines: Rocket Drill Safety Manual
/way #2214 68.02 96.50 2 Read Between the Lines: Extractor Drill X-78 Safety Guide

In case people didn’t know, you can type /ttpaste to get a window where you can paste all of the TomTom commands above in one go.

Managed to grab it day 1 easily(I really wanted the background, lol)

Honestly the hardest part was the cans, funnily enough. And even then you can kick each can multiple times, so it's pretty quick.

Do keep in mind that for most of the lore books you need to complete chapter 4 - they won't show up otherwise