Horiyos 13b - olive oil is good for the memory. Also dipping the fourth finger in salt prior to Birchas haMazan and licking off the salt. Yerushalmi Brachos Chapter 5 Halacha 1 - learning inside a Sefer is good for the memory. Otzar Segulos page 9 - saying Zicharon L'Maaseh Braishis at Kiddush...