How to sew insertion lace

When I do insertion lace, I pin the lace into position, then baste it by hand. Next, I sew with my machine set on a small stitch per inch, about a 2.0 mm. (on my old Kenmore it is 12 st/in) and sew as close as possible to the header (the straight area just inside of the outer edge of the lace) on the right side of the lace. Then I repeat the process going down the other side. After giving this section a good pressing,not ironing...(when you press you lift the iron up and move it to another section; ironing is leaving the iron on the fabric and moving it back and forth or in a circular motion.)  I cut the fabric behind the lace down the center using my applique or "duckbill" scissors. I press the fabric away from the lace and set my machine to a tiny 1.5 mm.(12 sts/in) zigzag, and sew over the previous stitching. Another pressing, and I trim the fabric away from the lace, as close as I can get it.

Use lots of pins and do this on a flat surface. I like to use my ironing board; the surface is pinable, so I can pin the garment section so it won't move around.  The ironing board hight is adjustable, so I can be comfortable standing or sitting.

Use lots of pins!!!

This really is not a difficult technique, but it looks like it is and has been used on garments for several hundred years. You need to take your time with each step and be as precise as possible. Sew slowly and accurately. Starching your fabric and laces makes them easier to handle and your finished product looks more professional.  Practice with scraps of fabric and laces. I would never try out a new technique on an actual garment. That is a recipe for disaster!  Experiment with the settings for your machine. I recently bought a new (used) Janome Sewing/Embroidery machine. The settings were quite different from the ones I used on my (36 yr.) old reliable Kenmore. They are also different for each type of fabric and each type of lace.  You may need to use a different size needle. I prefer a smaller 9 or 10, but you may like the results you get with a larger one.  Play and have fun!