Exculuding classical support traps, the gadgets, and tin gold fish, kagetokage, and goblindbergh, here are some other tech I've been testing.(Main deck only)
1. Iron call
Well, the iron call is what id call a must. It gives you a free xyz as long as you have a gadget in your hand, and of course, a machine in your grave.
2. Pinpoint guard
A free gadget in your hand, a undestroyable defender gadget in your field. What more do you want from life.
3. Pot of avarice.
To return xyz and precious gadgets to the main deck
Any other ideas? PM or post