When creating campaigns, we recommend a mirror campaign structure. This means that you want a corresponding manual campaign for every automatic: with the same ad groups and same SKUs within each ad group. This allows for easy transfer of data from search term to keyword.
Create campaigns per product category so you can set MACS, control budgets and achieve objectives at the campaign level. Use ad groups to group similar objects together and take keyword actions. This also allows you to group together SKUs with similar margins and analyze profitability.
Next: Audience Based Campaign Structure