I use "used fabric softener sheets" as backing on my Sues/Sams.
Just machine stitch around outer edges of each pattern piece( I trace these onto the fabric softener sheet) ... place your fabric
with right side facing the sheet, sew on drawn lines, trim 1/4" from drawn lines, clip curves, turn inside out, press, and you are ready to hand or machine applique onto your background block.
You can do lots of pieces while watching tv, and assemble Sue
later.