First, choose a size for the slip. If you're between sizes, it's a pretty safe bet to size down. We're using a two-way stretch fabric which is very forgiving. Knit undergarments are best fitted, rather than having extra ease.
If you're one size on the top and another on the bottom, it's easy to make a custom-fit pattern. Let's say you're a 14 above the waist and a 16 in the hips. All you need to do is draw a new pattern line that tapers from the 14 at the waist to a 16 at the hip. Here's what that looks like:
When cutting, make sure to follow your new line!
Note that this pattern includes A/B, C, and D cup sizes, so choose your bra pattern piece accordingly.
As for the panties, they run true to size. However, if you have a large bottom/hips, I would definitely recommend going with your hip measurement. I designed these panties to have full butt coverage (my pet peeve is undies that cut across the butt cheek--ugh!). To get those benefits, you need to use your measurement from the largest part of your butt.
To give you a sense of sizing, my measurements put me solidly at a 16. However, I cut a 14 in the slip to get a close fit, since I intend to wear this under dresses and skirts. In the panties, I cut a 16 since I have a big butt. (It's true.)
In my next post, I'll show you how to do a full bust adjustment if you're larger than a D cup. See you soon!
Previous sew-along posts:
Slip Sew-Along #1: Inside the Kit, Plus Other Supplies
Slip Sew-Along #2: Pre-treating Your Fabric