The word cottagecore seems to be in vogue these days.
It also refers to a style that is built on the idea of living in a rural cottage.
On YouTube,Rosery Apparelshows us how to do it quickly and easily.

Image credit: Rosery Apparel on Youtube
To top it off, your ruffled cushion will include a hidden zipper!
Cut one 15 cm 4 meter cloth rectangle for the ruffle.
Its possible that youll have to cut it into four parts.

To begin, secure the zipper.
Using an iron, press the edges of the longest rectangle.
Pins were used to secure the zip on the folded section.

Sew it to the fabric with a needle and thread.
Then, using an iron, push the edges of the bigger rectangle by 2 12 inches.
It should be pinned in place.
The zipper should then be sewn in place.
You now have a square that matches the other square cloth in size.
Begin by folding the cloth rectangles in half and pressing them with an iron to create the ruffle.
Stitch the shorter ends together after folding the cloth into a loop.
Then continue sewing the fabrics long ends.
Then gather the cloth into ruffles until it reaches the 40 x 40 cm square fabrics outside edge.
Stitch the gathered ruffles to the square fabrics edges once theyve been collected.
Then, to finish the cushion, sew around the whole edge of the square cloth.
Trim the extra fabric once it has been sewed together.
Then flip the pillow over to the correct side.
Using a ripper, remove any exposed collecting stitches.
Finally, press the wrinkles out of your cushion.