One of the easiest ways to show and not tell is by making your characters do things while they are talking to somebody or thinking about something. It could be anything including a chore, a daily grooming ritual, a hobby, or a group activity.
When you do this, you show who the character is by the things they choose to do or have to do. You also have to think about their body language, because the way a character does something says as much as the words they are speaking as they do it. [Read Cheat Sheets for Writing Body Language]
Try to avoid the act of scrolling through cell phones. Even if many people do this, it is passive and does not allow for movement, thought, and changes in body language.
Choose activities that fit naturally into your characters’ lifestyles. Do not force them to do things unless you mean to make them uncomfortable. [Read 5 Simple Ways To Describe Characters]
If you are stuck for ideas about what your characters can do when they are thinking about something important or while they are having a conversation, I’ve put together a list of suggestions.