What's a good practice/substance for setting your Arduino/sensors/devices on?

I'm just getting started in this world and I have a lot of Arduinos, sensors, pi's, and stuff with soldered pins in them sitting on my workbench.

I don't want to mess them up. Do I need to buy foam or something to set them on? Is it OK to leave them in the open air when they are part of a work-in-progress or do I need to store them in those anti-static bags that they get shipped in?

Thanks in advance

I have not found it necessary to take particular precautions on this front. I put them in static bags for long-term storage (and of course for storing inventory), and when I'm moving them around, but not otherwise.

I have a few drawers full of pro mini's and tiny 841/tiny1634 boards that I use for testing and development, and I've get to have any failures that I couldn't account for through some other sort of abuse.

The chips do seem pretty hardy once installed onto a card.
Bare parts, keep those in anti-static packaging, and discharge yourself by touching something metal before handling them.