It looks like moss stitch. Or seed stitch. Do you have a similar sweater that is that loose fitting? If so, measure it. This looks like it's made of rectangles. I am not good without a pattern either. That said, if you get the yarn you like, make a swatch to see how many stitches you need to cast on. Rib in what ever rib pattern you want for 2-3 inches. Start the moss/seed stitch, which ever you choose and knit until you have it to where you want to start your under arms. I see no shaping here. Knit maybe an inch more and decide where you want the neck opening. Here I would maybe cast off 4 sts at the center point. From here you will work one side and then the other for each front and all the way across for the back. (I am assuming you would knit the body in the round. I would!) Seam your shoulders. Pick up stitches around each arm hole and the neck line. You can do several finishes here. Maybe an add-on I-cord edging, or just a few rows of ribbing to match the bottom. Hope this helps!

Or you could do it in pieces. Make a paper template and knit your pieces to fit the template. I haven't tried this yet, but it sounds like it would be simple to do. I know a lady who did a beautiful jacket this way! She said she made the paper pattern and cast on to fit the edge she wanted to start from. Where she wanted decreases or increases is where she put them, laying the knitted piece on the paper to see what needed to be done where.

Tami

That is SO beautiful!
Unfortunately, I am not of a shape (or of an age) to successfully wear that sort of top.
And I absolutely detest moss stitch!
Good luck to you.