Now up to the fun bit...sewing it all together. I have broken this tutorial into several parts, just because the post is rather picture heavy.
Layout the pieces as they will be assembled. There are notches on the pattern pieces to assist you in laying them out. If you lay them out neatly as you work, there will be less chance of putting in a piece upside down or back to front. The bikini top uses pieces 7, 4, 5 and 6 as well as the strips cut for the tie.
The bottoms use pieces 1, 2 & 3.
Assemble pieces 4, 5 & 6 as you have laid them out (do not attach the neck strap yet). You can use either a narrow zig-zag stitch or an overlocker to assemble the pieces. In this tutorial, I have tried to show both methods where possible. The photo below shows the zig-zag stitch. If you are concerned about the width of zig-zag to use, pull on the seam after you have sewn it, to stretch it and check that the stitched do not pop.
Lay the assembled bikini top pieces over the lining pattern to check that everything has been assembled okay. You may want to use a stitcky dot to mark the neckline edge. The neckline edge is straighter than the armhole edge, but it would be easy to get them mixed up.
Lay the bikini top pieces over the bikini top lining. The lining pattern is the same size as the outer pieces.
Ideally, the lining should be a smidge smaller to allow for the turn-of-cloth when you fold the elastic in. Different lining fabrics will behave differently, so the pattern has not been modified to allow for this turn of cloth. You could cut the lining 1-2 mm smaller aIl the way around if you wanted a neater finish. It should not affect the appearance of the bikini when worn, as both the outer fabric and lining are required to stretch to cover the body.
I have seen some lining fabrics relax and end up bigger than the pattern from which they were cut. If this happens, lay the pattern over the top and cut again.
Assemble the bikini bottom pieces, again using either a narrow zi-zag or an overlocker. Lay the bikini bottom, wrong side down, on a flat surface, with the front waist uppermost.
Fold the back of the bikini bottom up over the front, so that right sides are facing in.
Fold the lining bottom in the same way, with right sides facing in (the right side is the side that touches your skin).
Lay the lining over the bikini bottom, matching side seams. Stitch the side seams.
This photo shows the side seam stitched.
Fold the front half of the lining to the front of the bikini bottom. See how the seam allowances are hidden and won't be rubbing against the skin. The lining is attached the bikini and won't slip around. You won't need to fuss around matching seam lines.
Turn the bikini right side out.
I'll attach the elastic in the next tutorial.