You can achieve it with CSS. I think it can vary from device type to device type, but for switches, I have used the CSS below to insert a name, remove the icon, and hide the tile title. You may also be interested in the CSS thread for some other ideas on modifying your tiles.
/* Switch Titles */
#tile-89 .tile-primary:after{ content: "NEWS TIME"; }
#tile-90 .tile-primary:after{ content: "CLOSE ALL BLINDS"; }
#tile-91 .tile-primary:after{ content: "SWAP TV's"; }
/* Switch Icons and Title Hiding */
#tile-89 .material-icons, #tile-90 .material-icons, #tile-91 .material-icons { display: none; !important; }
#tile-89 .tile-title, #tile-90 .tile-title, #tile-91 .tile-title { visibility: hidden; }
I say that like everyone knows how to update the CSS on a dashboard.... 
To apply this, find out the tile Id you want to change on the dashboard by clicking on the 3 dots on the tile, the id is in the top left of the dialog. Close the tile editor and click on the cog icon, click Advanced, CSS and then enter the CSS you want to use, replacing the Tile Id's in any of my example (if you use it) with the tile id on your dashboard.
