Let's assume your ownCloud instance is accessible on https://domain.net/owncloud.
As always, there is still Archlinux wiki : https://wiki.archlinux.org/index.php/Owncloud
Here, with an account “user” :
Add a caldav account and set remote address (with a calendar named “calendar_name”) :
Add a carddav account and set remote address (with an address book named “addressbook_name”) :
Better using DAVdroid now.
If https is used with a self signed certificate, CAdroid can be used too.