T'au Drones (gun drones, shield drones, marker drones, and others) sit on small flying stems atop small bases. The recommendations below cover the flight stand, base magnets for the round bases, and disc magnets for swapping drone variants.
Flight Stands for Drones
The Extra Small Flat Magnetic Flight Stands suit T'au Drones. The flat top keeps the drone level on its stem and the magnetic base lets you lift each drone off the table without knocking neighbors.
[Buy Product=warhammer-40k-medium-sall-flat-jetbike-stand-posable-magnetic-flight-stand,Variant=All]
To swap between gun drones, shield drones, marker drones, and other variants on the same stem, use 3mm x 2mm disc magnets between the drone body and the stem top.
[Buy Product= 100pcs-3mm-x-2mm-1-8-x-1-16-disc-magnets,Variant=All]
Base Magnets for Drones
Base Magnets let you lock each drone to a metal sheet inside a magnetic miniature case so transport stops being the part of the hobby that breaks models. For drones with the standard small round base, the pre-magnetized replacement base drops in with the magnet hole already set.
[Buy Product=bases-premagnetized-warhammer,variant=32508936716372]
If you want to keep the original clear small flying base, the 32mm self-adhesive magnet is the cleanest option. It sticks to the underside without drilling through the clear plastic. If you have 2mm thick magnets and don't mind drilling, 2x2 or 3x2 disc magnets also work.
[Buy Product=flexible-self-adhesive-magnets,variant=32934330269780]