Best Practice and way to Control the method access in Worksheets

Hi Gurus,

we have a requirement to control access to member methods such "Add Item", Edit Item, "Delete Item" and so on for all other levels. I would like to understand what is best practice in setting up controls based on the role?  Can we make user of the user groups?

Currently our system access to every one to all methods.

If I have to have revoke the methods access to all user and keep it only for two users to do "Add Item", Edit Item, "Delete Item".

Do I need to revoke every thing at component level first?

Followed by user permission levels?