Once you feel confident, or have had a go at the basic and intermediate styles, you could move onto these designs.
This pattern adaptation for a gathered neckline uses the 'slash and spread' method. Evenly mark vertical lines through the pattern, 'slash' down the lines and (keeping the bottom edges together) evenly 'spread' the pieces. Stick your new pattern down onto a backing paper. You will need to smooth the neck and hemlines (in green). You could reverse this method and make a flared hem/ trapeze/ swing top instead.
If you want to add buttons at the shoulders, you will need to add a facing to get the best finish. You will need to add a button stand (1/2 inch either side of the shoulder line) first. Then use the front and back patterns to draft a facing pattern onto, as diagram. This is really easy to construct: Stitch up the sides of the top and the sides of the facing; pin the front facing to the front top and the back facing to the back top (right sides together); stitch all the way around the armholes, shoulders and necklines; clip corners and curved seams; turn inside-out and press; edge stitch if necessary. Consider whether to put the buttons on the back or front, mark on, make buttonholes and attach buttons.