Add a name, a date, or words to any pattern to personalize it. Search through pattern books for an alphabet that has an appropriate size and theme for the piece.
If the floss in a kit is not the quality you were hoping for, you can replace it. If the kit includes the color codes, it will be very easy to translate them to a better quality of floss. If not, you will need to match the colors as best as possible in natural light.