Communing with Yoda seems the obvious thing. But Frink has Yoda chuckling at sensing Anakin’s agony. Ric’s ghost could appear in the funeral scene? Or take part in the Tantive conference room scene between Bail, Yoda, and Obi Wan?
Ric could also appear to welcome Yoda to Dagobah, if you use the deleted scene.
And what of Spock?