Tech threads are my favorite threads. Hit me with your pet tech cards and the Commander that synergizes.

I'll start with this one, but I'm sure I'll post more.

Another!

Hint: Rak can reduce alternate casting costs.

This isn't a commander pairing, but Flagstones of Trokair is solid tech in any deck with Harrow, Springbloom Druid, or Crop Rotation. You won't have them together all the time, but when you do... magic.

My Phelddy deck wants to be dumping its mana into hippos anyway, so doubling them up for card draw is huge.