On segulos, palm reading, and similar practices in shidduchim, the Rebbe's guidance:
Go with Torah and trust in Hashem, not superstition. Choosing a shidduch should be guided by Torah values and bitachon rather than superstitions or customs found in various books; focus on the essentials and proceed with faith and simplicity (IK 5974). Disregard palm reading; with sincere effort in line with the Torah, one receives help from Above (IK 2848).
Palmistry and marriage compatibility are discussed in Kabbalah, but one may rely on such knowledge only if it was received authentically from a teacher. Better to put the effort into learning Chassidus (IK 5383).
For the spiritual steps the Rebbe did recommend, such as checking tefillin and mezuzos, daily tzedakah and Tehillim, see: שידוכים – קשיים במציאת שידוך.