You could do up a biography of the person you have in mind and see if there are others who also believe as you concerning that person’s holiness. There is nothing wrong with printing a picture of that person for private veneration.
There was a process for the canonization of the English King Henry VI which his successors supported until Henry VIII’s rift with Rome.
Catholics went on pilgrimage to Windsor to visit “Blessed King Henry’s” tomb and there were even pilgrim badges made and images of him with a halo (in those times, local cults of uncanonized holy ones were much more overt than today).
People also lit candles before his picture and this was called “King Henry’s Light.” Should he have been canonized as “St Henry, King and Confessor” he would have been enshrined in Westminster Abbey, but that was not to be.
During the pontificate of Bl Pope John XXIII, an Anglican minister met with the Pontiff and then pulled out his rather tattered Breviary. The Pope, upon seeing the sad state of his breviary, offered the minister his own.
The Anglican minister, however, pulled from his breviary a picture of “Blessed King Henry of Windsor” that depicted him with a halo and began to explain to the Pope about the private veneration of that king by English Catholics.
Right there and then, Pope John called a Cardinal over to himself and renewed the Cause of King Henry VI!
There is a Society of King Henry VI today with members including both Catholics and Anglicans (and anyone else who is interested in the Cause). The Pope also granted to members the privilege of publicly invoking the king as “Blessed King Henry” in their association prayers.
Alex