Here's a tut for making an empire-waisted apron, with a bit of gathered detail (hard to see with this fabric) on the upper bib part of the apron.
For the waistband sash, cut out 2 strips of fabric that are 5.5" x 42"(ish). Cut one of those strips in half again to create pieces that are 5.5" x 21" (ish). You will now have 3 pieces of sash; one long one and two short ones.
For the apron skirt, cut a rectangle that is 26" wide x 19" high.
For the apron skirt accent strip, cut a rectangle 26" wide x 4.5" high.
For the apron top, cut a rectangle 16" wide x 5.5"
For the apron top accent strip, cut a rectangle 12" wide x 4.5" high
For the neckstrap, cut a strip 25" x 2.5"
First, sew the accent strip to the apron skirt. With right sides together, stitch (using a serger or overlock stitch on this seam will contain all the loose threads) and then press seam upwards. Turn under bottom hemline 1/4", then fold over again so all raw edges on bottom are hidden. Press well, then stitch across bottom hem.
Now is the time to stitch a ribbon accent to the bottom if you would like to.
Fold over and press the sides of the apron skirt just like you did to the bottom hem. Stitch closed and give the whole apron skirt a good pressing.
Take the apron top (the one that's 16" x 5.5") and, starting 5" in from either side, make long basting stitches in the middle of both the top and bottom of the rectangle. Gather the basting stitches, adjusting so that the rectangle ends up being exactly 12" to match up with the accent fabric. Gently press the gathered area on the edges and stay stitch the gathers with a normal length stitch size.
Putting right sides together, stitch the gathered part to the accent part. Press the seam upwards. Turn the top of the accent piece under 1/4", then fold accent piece over so that it covers the seam that holds the two fabrics together. See photo below for reference.
Now is the time to sew some accent ribbon across the front of the apron top, if you so desire.
For the neckstrap, carefully turn and press under 1/4" along both sides of strip (work hard to make them as even as possible). Fold in half lengthwise so that the raw edges are completely hidden. Press firmly and carefully.
To attach neckstrap to apron top, first decide how long to make the neckstrap. I have a lot of extra neckstrap fabric tucked into the sides of the apron, about 3 inches on either side. This measurement will vary from person to person.
First press under 1/4" on either side of the apron top, then fold over again to exactly the width of your straps so the straps can be encased within the folds. Press sides, but don't stitch yet. Pin the strap where you think you want it, and slip it over your head to make sure you can fit it over your noggin and that the apron top ends where you want the waist sash to be. Remember that this apron is designed to have a higher waist than your natural waistline.
Once you have the strap pinned at the desired length, and the sides are folded and pressed in place around the straps, stitch across the very top of the apron to secure the straps. Then stitch down the sides to secure the side flaps that are turned under. If you have accent ribbon, you may want to avoid sewing over the ribbon if your thread is the wrong color. I was using black thread, so I stopped stitching just at the ribbon as I was stitching down the side flaps, and I started stitching again right after the ribbon.
Here's another view of the back side of the apron top.
The final step for the apron top is to serge the bottom raw edge or sew a bit of double wide bias tape to the bottom raw edge so you won't have a bunch of unsightly loose threads hanging down.
The apron top is now ready to attach to the waist sash, but first you'll need to get the sash ready. These pictures show it already attached, sorry for the confusion. Yours won't be attached yet.
Trim off the ends of sash at an angle. Mine is trimmed with a 2" difference, and the long point is at the fold - not the open side.
To finish the ends of the sash, flip it around so that the right sides face eachother. You may want to press the folds back out flat at the very end of the sash, and you can clip that little triangle off if desired.
Starting at the pointy tip, stitch 1/4" seam down the angled edge, then down about an inch (or more...I wish I had sewn mine a little further down than I did) further on the long side. This will give you a nice finished end to your sash.
Trim the end and the corner off as shown. Turn right side out and fiddle with the corners until they are nice and pointy. Press the ends of the sash.
Now it's time to attach the sash to the apron skirt! Mark the center of both the apron and the sash with a pin, and with right sides together and the sash centered over the apron, pin in a few places. Take the iron and lightly open up the pressed-under part of the sash that covers the apron. I shouldn't have ironed that part in the first place, but it only took a few seconds to press open again. On yours, if you wish to take the time and measure what part of the sash will be centered over the apron skirt and not press under that seam in the first place, go for it! :-)
After pinning the sash, stitch 1/4" seam to connect the sash to the apron skirt. Press seam up toward sash. Then fold sash over and pin in a few places to make sure it covers the raw edges of the seam you just sewed. Stitch all along the bottom edge of the sash to close it all in. This way you avoid having to sew the entire sash inside out and then turn it right side out and press it carefully (for that method, see my tutorial for the reversible cafe apron). Either way has its pros and cons, I'm not sure which way I prefer yet.
Now just slip the finished apron top behind the finished sash and topstitch in place. I then topstitched all the way across the top and tips of the sash for added durability.
All done! Time to get cookin'!!