The easiest way to do it is go to hivetasks.com/@youraccountname
Then open the Tools tab and from there Account Creator:
When you click on Account Creator, you'll see this:
Then you need to claim an account ticket. Make sure you have Resource Credits selected as payment method. Just click "Claim Account".
NB: You need to have at least about 4000-5000 HP to be able to claim a single account. Creating an account is that expensive in terms of Resource Credits. The alternative is to pay 3 HIVE for an account ticket.
NB2: Claiming account tickets continously is probably a good idea even if you don't have any use for them yourself at the moment. They might be made transferable in some future hard fork. They are currently worth 3 HIVE each, which means that if you have claimed hundreds of them, it means that you could be in possession of a nice chunk of change in the future!
Then you can use the Account Tickets to create accounts.
Teach whoever you onboard to change their own master keys they get from you. Also have them use a password manager to store all their keys. Tell them to store the encrypted key files on multiple physical devices, each stored safely.
Also teach them to use Hive Keychain, which you can download from here:
https://chrome.google.com/webstore/detail/hive-keychain/jcacnejopjdphbnjgfaaobbfafkihpep