When you have multiple clients, do you use your own master Google account to set up all your clients in, OR do you set up all the Google services for each client in their own Google account?

For example, when you have a client who wants you to manage their MyBusiness, Analytics, Search Console, AdWords, Tag Manager, etc. (and all the validation that goes with setting these up) - do you do it in their Google account or your master account?

I know you CAN add other users as admins to specific Google products, but I can't seem to figure out how to do it at a global level. Is that even possible? Or is it only at the Google product level for each service? I can't seem to find any videos or tutorials online to answer these Qs.

Also, do you find it easier to 1) make clients users on your master account, or 2) yourself a user on their account (in the case where they already have it established, or 3) set up a new shared account with email forward as the designated email on the account? How do you avoid having to share a password with your client? Get around being able to only list one phone number for validation to login?

It looks like this post partially answers my Q, but not fully: How to manage Google Webmaster Tools for Multiple Clients - When you create a shared account, Google starts being a pain with verification when they notice logins from different locations, and you have to use one phone # to verify identity to login.