Here are the simple pattern pieces that make up the top I'm wearing this week in my Look What I Made post. The sleeves are exactly the same shape, the neckline can be any shape you want and the front and back combined distance between the large Xs should be at least equal to your bust measurement.
Step one is sewing the sleeves to the front and to the back.
Step two is sew the shoulder seams
Step three is sew the neckband on ( see following directions )
Step four is hem the outer edges of the sleeves
Step five is sew the front to the back ONLY BETWEEN THE LARGE AND SMALL Xs
Hem the bottom and enjoy your new top!