1. Choose the right number of strands for the count of fabric you are using.
2. When using blending filament, tie it in a simple knot at the end of the needle to prevent it from slipping through as you stitch.
3. Use the loop method to begin stitching with shiny or slippery thread such as rayon or metalic
4. For a neater finish with fine metalic threads , stitch with single a strand and stitch each arm of cross twice.
5. If you experience problems with threads twisting up, stop from time to time and let the needle hang down below the fabric to remove the excess twist.
6. When using stranded threads, separate each strand and then put the required number together again before threading the needle. This will make thread easier to stitch and produce a much neater result.
Source : cross stitching magazine.