These are the instructions for erasing data. Find the one that applies to your device. We need ALL Apple devices to have their data erased (it's fairly simple) to make sure we can use them. Email contact@projectboom.org with questions.

Before you sell or gift your Windows 10 device or Xbox One - Microsoft Support: https://support.microsoft.com/en-us/help/10547/microsoft-account-selling-gifting-windows-10-device-xbox-one

Windows 10 basics: how to reset your system - The Verge: https://www.theverge.com/21264104/windows-10-reset-os-reboot-troubleshoot-microsoft

Recovery options in Windows 10 - Microsoft Support:  https://support.microsoft.com/en-us/help/12415#section2 and pick "Remove everything"

How to refresh, reset, or restore your PC - Microsoft Support: go to the "Reset PC" section - https://support.microsoft.com/en-us/help/17085/windows-8-restore-refresh-reset-pc

Instructions in progress, you will likely be able to find something if you look it up with a search engine. Email contact@projectboom.org if you need help with this and someone will get back to you soon.

What to do before you sell, give away, or trade in your Mac - Apple Support: https://support.apple.com/en-us/HT201065

What to do before you sell, give away, or trade in your iPhone, iPad, or iPod touch - Apple Support: https://support.apple.com/en-us/HT201351

For other types of devices you can often look up "how to reset [device]" in a search engine. If that does not help email contact@projectboom.org.