Here are a few samples of how adding pleats to a pattern can change the look.
The first outfit is made from New Look Pattern #6473. I shortened the pants a little and added long pleats in the same fabric as the top. Using the stripes in the fabric made it easier to make the pleats equal.
For the dress I used McCall's pattern number M4422. I replaced the gathered ruffle directed by the pattern and used pleats instead.
Both of these were made using my basic Annette sundress pattern. By adding straps instead of loops and a row of pleats along the bottom. I shortened the dress in the first outfit and added capri pants.
I like lining things when possible. The two dresses as well as the hot pink top are fully lined.