Birchas Habanim: Blessing ones children prior to leaving for Shul:
On Erev Yom Kippur, after the Seudas Hamafsekes but prior to leaving to Shul for Kol Nidrei, it is accustomed for parents to bless their children [with the priestly blessing of “Yivarechicha Hashem Veyishmirecha”]. They should cry to Hashem that their prayers are accepted and their children be sealed for a good year spiritually and physically. It is customary for mothers to likewise bless their children. The Rebbe Rashab would place his hands over the heads of his granddaughters when saying the blessing.
The Nussach of Birchas Habanim: The Rebbe was accustomed to beginning the blessing from “Vayidaber Hashem El Moshe Lamor….”. However, some are accustomed to reciting “Yesimcha Elokim Kiefraim Ukiminashe”.
Placing the hands on the child’s head: The prohibition against a Non-Kohen reciting Birchas Kohanim applies if one raises his hands, similar to a Kohen, upon saying the Birchas Kohanim. Due to the above prohibition against lifting the hands, some are accustomed not to even rest both hands on the head of the person being blessed when blessing him with Birchas Kohanim, and rather rest only one hand on his head. Other Poskim rule it is permitted and encouraged for one to do so. Practically, the widespread custom is to be lenient and allow the placing of two hands on the head of the person being blessed, and so was the custom of the Chacham Tzevi and Rebbe Rashab.
 Mateh Efraim 619/2; Kitzur Shulchan Aruch 131/16; Sefer Haminhagim p. 124 [English Edition]; Otzer Minhagei Chabad p. 194
 Sefer Haminhagim ibid
 Mateh Efraim ibid
 Hisvadyos 1987 Vol. 1 p. 131; So is the Rebbe’s custom in Birchas Hatemimim [Sefer Haminhagim ibid], and so is implied from Kitzur Shulchan Aruch ibid. to say the blessing of Yivarechicha. It is not mentioned in Sefer Haminhagim the dialect of the blessing. Regarding the issue of a non-Kohen reciting Birchas Kohanim see Otzer Minhagei Chabad p. 195. The M”B 128 in Biur Halacha “Zar Over Beasei” rules the prohibition only applies when one raises his hand.
 Kitzur SHU”A ibid
 Kitzur Shulchan Aruch ibid; See Otzer ibid that the Rebbe Rashab would go to his mother to receive a blessing.
 Otzer ibid
 See Piskeiy Teshuvos 271/1 footnote 5
 Admur 128/2; Rama 128/1; Kesubos 24b
 Bach 128, brought in M”B 128/3
 Custom of Gr”a, brought in Torah Temima Bamidbar 6/23; Siddur Reb Shabsi; Maavor Yabok Sisei Renanos 43; See Piskeiy Teshuvos 128/6
 Siddur Yaavetz Seder Leil Shabbos; Sheilas Yaavetz 2/15 that so was the custom of his father the Chacham Tzevi
 See Daas Sofer 1/14; Beir Moshe 4/25; Tzitz Eliezer 11/8; Yechaveh Daas 5/14
 Brought in Sheilas Yaavetz ibid
 Otzer Minhagei Chabad p. 194