The most straightforward rule to remember if you’re trying to show is merely to be specific. Specificity will fill in the gaps from your telling and bring life to your scenes.
Here’s a very tell-tale example:
They went to New York to see Cats. They both enjoyed it very much. When they tried to go home, their flight was delayed because of the snow, so they stayed another night and decided to see the musical again.
That’s a fun story. It’s all pretty vague, though, isn’t it?
Who is “they”? At what theatre did they see Cats? Why did they enjoy it? How did they feel after their flight was delayed?
Here’s that same example with some of those questions answered:
Tanya and James flew to New York City. “I can’t wait to see the show,” Tanya said as they checked into their rooms. “You’re going to love it.” James shook his head. “I don’t get it. It’s about cats who sing and dance? Sounds sorta dumb.” Tanya smiled. “Just trust me.”
Their hotel was just a few blocks from the Foxwoods Theater, so they walked. James had never seen any buildings so tall or so many people walking on the street before. When they got to the theatre, Tanya noticed his eyes were a little more full, his mouth a little slacker.
Those two paragraphs are not perfect, but it’s a little better. Instead of “they,” we now see Tanya and James. We know a little more about them, that Tanya is a little more cultured, while James is more wary of it.