Gridfinity is one of those systems that sneaks up on you. You print one baseplate and one bin. The bin fits. You print another bin. That one fits too. Three months later your slicer history is full of rectangular thumbnails, your hex keys are sorted by size for the first time in recorded history, and you're explaining to someone at work why you need a 3D printer "for organisation purposes."
The system was designed by Zack Freedman and released as an open spec in 2022. The core idea is simple and good: baseplates built on a 42mm grid, bins that snap onto that grid, and a spec that anyone can design for. Because the standard is public, bins and baseplates from thousands of different designers are cross-compatible. A bin from Printables drops straight into a baseplate someone designed on MakerWorld. The ecosystem is enormous, it is entirely free, and the defaults are genuinely well thought out.
Start with the baseplates
The first print in any Gridfinity setup is a baseplate. The Gridfinity Base Plates Pack 1x1 to 10x10 by gege (Printables) covers every grid size in one download. Print the one that fits your drawer or shelf, and everything else you print from this point will land on it correctly. A 3x3 or 4x4 is a good starting size; the footprint is close to a standard desk organiser and holds enough bins to be useful.

For the workshop drawer
The canonical Gridfinity print is the Gridfinity Allen Key Tray by taqTokToe (Thingiverse). It fits a 3x3 grid, holds metric keys from 1 to 10mm, and slots are labeled by size. No supports, no magnets required. It is the print that converts most people from "I could try that" to "I should probably print more of these."
Once the hex keys are handled, the Gridfinity Tool Holders by Packet2 (Thingiverse) covers socket sets in 1/4, 3/8, 1/2, and 3/4 inch, metric and imperial, with the brand and size labeled on every module. The same designer also made the Gridfinity Wrench Organizers for larger drawers. At some point you stop buying storage products and just print them instead, which is the correct outcome.

For the desk
Gridfinity works on a desktop as well as it does in a drawer. The Missile Turret Pen Holder by BiggBadaBoom (Thingiverse) is a Gridfinity-compatible pencil holder shaped like a missile turret. It holds 12 pens, fits a 2x2 grid, and prints in three pieces. If anyone asks, it is an organisational tool.
Where it goes from there
The Soup Can Dispenser, Gridfinity Edition by voinivich (Printables) is an FIFO-style can dispenser with a 5-deep Gridfinity base on top so you can stack bins above your soup storage. The system has reached the kitchen. Your pantry can now be modular. There is no obvious end point to any of this.

The Gridfinity MTG/TCG Storage System by zuidec (Printables) takes the same 42mm grid to the card gaming table, with deck boxes, token trays, and sleeve holders that all live on the same baseplate as the workshop. At this point the grid is a lifestyle.

A few practical notes before you start
Most Gridfinity bins print in PLA without supports at 0.2mm layer height. If you want the magnetic snap, you need 3x6mm or 6x2mm rare earth magnets pressed in before the top layer closes; pause the print at the right height and drop them in. Without magnets, bins still sit and stack securely enough for drawers. The magnets matter more for surfaces you'll pick up and carry, or for vertical mounting.
Thinger's Gridfinity collection has 40 models sorted by how often they get saved, updated as new designs trend. If you want to work out the filament cost before committing to printing 30 identical bins, the print cost calculator will tell you the number before the spool gets involved.
The free Thinger app lets you search over 600,000 free models from Thingiverse, Printables, and MakerWorld. For Gridfinity specifically, it is worth searching by your tool brand name: the ecosystem is large enough that a holder designed for your exact multimeter or screwdriver set often actually exists.