What You Need
FIRST You need to download this pattern and print it on a paper then cut it out.
TWO Attach the pattern parts to the lace, place the straight edge of the pattern on the edge of the comb lace. To avoid the scattered lace edge, get rid of the pieces, just cut along the flat edge.
THREE You have 2 pieces. It is important to try to make the lace patterns identical on both sides, so if the lace pattern is made it will appear symmetrical.
FOUR Pin the edges together.
FIVE Sew along the curved edge leaving a seam allowance.
SIX Repeat the same process for the both sides.
SEVEN You need to take the thick elastic and wrap around yourself to measure how much elastic you need. Keep in mind that it is better not to make it long, its better when it is tighter.