You can set up cross-sell and upsell recommendations like this:

Cross-sell	Upsell

In both cases, you can set whether you want to turn on recommendations (enabled yes/no). Recommendations will only be shown when this is set to Yes. If you set this to no, only Magento's standard recommendations will be displayed.

NOTE: you can turn Tweakwise recommendations on in different locations in the Magento CMS.

You can set which recommendations template from Tweakwise should be used when selecting a template. You can also choose group code here. In that case, multiple rules could be used to determine the right recommendations.

Read this article to learn about group keys.