I just finished this long t-shirt dress with short sleeves and vertical darts.
...and side slits on each side seam
I used this McCalls 2460 pattern, designed for a woven, so I cut it a size smaller. I chose it for the vertical darts to give shape to the dress, and I (approximately) liked the neckline, so thought it was a good place to start. I eliminated the side seam dart (didn't need it on a knit), and shortened the sleeves a bit to make them closer to a cap sleeve.
I absolutely adore this ballet neckline variation created by Passiona Cottee on the Burda (Downloadable) Lydia t-shirt. (You can download the pattern for a dollar and see various adaptations discussed here.) I didn't quite achieve this neckline, I got nervous with the scissors so close to the edge of potential ruin... it's OK in this more modified version, but I'm going to try Passiona's on another shirt)
Next debate: Does the dress need a belt (either sewn on or just a tie belt.)?? I'm concerned that the loooong t-shirt is kinda looooong with nothing going on. Maybe it's OK ... I can't decide.
Option 1: Empire waist ... a bit too little girlish I think
Option 2: Just above the waist ... nice and tidy and adult-looking ... this works.
Option 3: Below the waist ... I like this one, and could do it with a white tie belt with the ends hanging down for visual interest... (any opinions out there)?