Spoke Tools

The first phase of wheelbuilding can use a screwdriver-like tool to tighten the spoke nipples, and this is much faster than the later phase using a spoke tool. The classic screwdriver tool looks like a regular screwdriver bent into a right-angle Z. I have no doubt that a seasoned builder could use such a tool with admirable efficiency, but as an occasional builder I haven't tried to find one.
Instead, I ground down a standard hex screwdriver bit, as shown. I used the edge of the grinding wheel to leave a pin in the center, which fits into the spoke hole in the center of the nipple. This works far better than a standard screwdriver bit because it keeps the bit centered and allows the bit to hold the nipple fairly well. (This shape is borrowed from the classic tool.)
I like this bit a lot. Its small size makes it a nice handle for inserting the nip and engaging the spoke, then a finger-roll or two engage enough threads to move on to the next. I can't think of a tool design that would make this process faster.
Later, after all spokes are installed, I use the bit to perform initial tensioning, until I need more torque than fingertips can provide. Then I put the bit into a small ratchet driver and work until that too becomes slow. Then the rim strip goes on for safety and I switch to the standard spoke tool which works on the flats exposed next to the spoke (and visible in a finished wheel).