Keeping the tables small but not repeating data.
1 - Each column can only have 1 value - address should just be street not city state and zip as well 2 - Each column should have unique data if there is a need to have repeat data in the table (like categories) then categories should be a seperate table and linked in. 3 - Table name plural and all lowercase (industry standard) 4 - id should be the primary key 5 - foreign keys should be named singular_tablename (user_id) 6 - Industry standard to have created and updated at
SELECT data WHERE condition INSERT data UPDATE data DELETE data