I've got some fit issues to correct under the arms, but I like this style and will make it again.
I love the gathered neckline.
Here's what I did:
1. Cut out around a shirt I liked in a similar style. I just had two pieces, a front and a back.
2. Stitched up the sides and shoulders.
3. Attached 1" single-fold bias tape at the raw edges of the neck and sleeves. I stitched just 1/8 inch from the edge at the neck, so that I would have a casing.
4. Added 3/8" elastic through bias tape casing at the neckline.
5. Secured the elastic at each end with a topstitch.
Here's what I learned - the sleeve fit is crucial. Next time I'll take a measurement at my upper arm before I cut.