Dear Sara, thanks for your inquiry. Depending on the purpose of the seam. I either cut the thread tails back to approx. 2cm / 1”, that is enough to keep the last stitches secured. Most often, I take all threads, twist them together and use a tapestry needle to pull them under the stitching between the fabrics, that makes the seam more durable for wear and wash. Hope this helps you find the solution that fits your needs.