Batch Cutting and Box Joints
You can make them one piece at a time, but it’s far better to tape your pieces together and cut them all together as a block. This gives protection against tear-out, as each one protects its neighbour, and it's fast.
For anything small or tricky it could be better to run through a solid block, making all the joints, and then strip it through the bandsaw piece by piece, planing the face of the block between each cut.
For example, a 3mm cutter making smallish boxes will need to cut a stack of material tracked east/west bringing the bit forward down the Guide Rail at 6mm intervals. This is easy to track on a 6 inch ruler screwed to the right hand Guide Rail.
The cut pieces might fit too tightly, as this could be too exact a pitch, especially if the bit has been sharpened and not quite cutting 3mm, resulting in undersized sockets and oversized pins and no room for the glue. The solution is to cant the scale on the guiderail at about 5° so that the scale reads a percentage less than 100 percent. The sockets will be the same size but the pitch will be tighter, giving slightly smaller pins. The result will be an easier fit.
Using the Block (featured under tenoning), you can cut box joints with two different diameter bits, and get joints of different sizes, which makes an interesting variation.