The best way to welcome the neshama yeseirah (the additional soul we each get on shabbos) is by sanctifying one’s thoughts and concentrating on attaining deveikus (closeness) to Hashem. The neshama yeseirah derives its highest exultation from our fervent kavanah (concentration during prayer), and from the Torah insights on the parashah we tell each other. ~ Reishis Chochma as quoted by R’ Dovid Meisels