The fact that they are rendered as text provides a good rule of thumb for when they are appropriate : 1. Can you read your sentence without reading the emoji t

The fact that they are rendered as text provides a good rule of thumb for when they are appropriate : 1. Can you read your sentence without reading the emoji text and it makes sense? 2. Can you read your sentence with the emoji text and it still makes sense (and it means the same thing, with emphasis added)? If the answer to both questions is YES, then using the emoji is OK.