He waited a while. Then he left.
He waited 10 or 15 minutes. He wasn't sure as the phone got no reception. Then he walked away.
One of the many distinctions between good writers and beginners is the specificity of their language. Any time you can be more specific in the plot or the description or the dialog, consider it. She had dark hair or she had dark chocolate hair? He wore long pants or he wore tan Dockers? He walked down the road or he walked down the dusty road seeking out the occasional shadow?
Notice that I say "consider it," not "do it." Because the other side of the issue for beginners is using too much specificity.
He ate his burger with ketchup, mustard, pickles, lettuce, tomato, and onion. And on his fries, he put extra salt and ketchup.
This kind of detail doesn't tell me anything special about this character. Of course, if there isn't anything special about him to know, then I don't need any detail. But if there is, how can you show me? Thus, the details can't be specific for their own sake, but to show us or tell us something. Here's another example:
He took the lettuce out of the burger and folded the lettuce so that it was the exact size and shape of the patty. He then cut the burger into 4 quarters. She wondered if he had a secret way to measure them for they seemed exact. Then he took out a towelette, washed his hands, and proceeded to eat the sandwich with his knife and fork. "I'll be you think I'm weird, don't you?" he asked.
The details here tell us a lot. He's precise, he's fastidious. Just the man she wants to do the job of killing her husband.
You may not want to worry about specificity when you're drafting. Now that I write every morning, I spend the first few minutes reading the paragraphs from the day before. While I'm not editing, I will note a place where I can be specific. This morning I added this detail.
Before: She dried off in front of the window, watching the women in the garden below.
After: She dried off with the only clean towel in the bathroom, watching the women hoeing in the garden below.
See what comes alive in your writing when you add a few specifics.