I am attempting to make a blousson style 2 pc suit. How do I figure how much ease to add to make the top fairly loose (around my waist). Thanks for any help anyone can give me!

Personally, I would not even need a pattern for a blousson-type swim tube top! The gathering above the bust and at waist virtually guarantees that horizontal fit won't be an issue. I'd just start with more or less a tube, with a length that's some fraction of the "Full Length Front" and "Full Length Back" measurements. The tube's width at the top would be the high bust measurement plus some amount for gathering, maybe 50%? Ditto the tube's width at the bottom.

If you really want to start with a Dress Shop pattern for this, I'd go with a "Crop Tank Top", with no front bust darts and no front/back waist darts, and a "fit" of "unfitted".

Thanks a lot Anna, I'll try that & see what happens!