I'm not sure exactly what you mean by it's too puffy..but after soaking it it's too stiff. Could you add some more details here? What kind of fabric is it? Is it a cotton, polyester or a decorator fabric? This might help with a solution.

Most fabrics that are washable can be washed 2 or 3 times in the washer and dried as many times, and it will help remove any sizing or treatment on the fabric. I sometimes throw a bath towel in while washing it to help "scrub" the fabric to help with making fabrics softer.

Woodsy

Maybe washing with a cup or so of vinegar in the water?????

Thank you both, the towel helped a bit. The word I was
looking for was relax the fabric. I have not sewn in about
25 years, I could have sworn there was something that would
relax fabric.

Repeated washing and drying relaxes fabric. Unfortunately, this sometimes fades it, too. The towel idea is good. When I fluff my down comforter, I add a sneaker to thrash into it during the cycle. Something else to try.

I have two new pairs of jeans that are so stiff I can't sit down in them. How can I get them soft? They are so uncomfortable.