I have made a number of these casual semi-fitted tees from Wendy Ward's book 'Beginners guide to sewing'. I really like the boat neck shape, the fact that it isn't too clingy and the cap sleeves. These can be made in a contrasting fabric so perfect for using up those jersey scraps! In some versions I have hemmed the tee to sit just on the waist so it can be worn with a full or gathered skirt. I love this sailor strip version because it just screams SUMMER!
I am also very happy with the swallow print grey marl version below. The hemline is kept long and tunic-y to sit nicely over skinny jeans.