Erev Rosh Hashana
- Some have a custom to fast on Erev Rosh Hashana until chatzos (midday). 
- One should participate in Hataras Nedorim (nullification of vows) after shacharis. At times we make promises and fail to keep them. Non-fulfillment of halachically binding vows is a serious transgression and as such we seek to release ourselves if we have articulated binding vows over the course of the year. One can recite this formulation in Hebrew or any language one understands.  
- Many have the custom go to the mikvah on Erev Rosh Hashana. 
While the day of Rosh Hashana can be viewed as a day of awe and judgment, the sages have taught us that we must go into the day with confidence and a feeling of celebration. Therefore, it is important to be well-groomed in honor of the day.  
- There is a custom to visit and daven at the graves of relatives and tzadikkim on Erev Rosh Hashana. We ask Hashem to allow us to utilize the merits of our ancestors. One should give tzedaka before praying at the cemetery.  

Rosh Hashana 
Shehechiyanu: The bracha of shehechiyanu is recited during kiddush and candle lighting.  

Simanim: There are various customs regarding the simanim (symbolic foods) that are eaten on Rosh Hashana. One should follow their family customs regarding what is included. If one does not have or know the family minhag, the following is a list of symbolic items which can be included:
- Challah dipped in honey  
- Apple dipped in honey 
- Carrots or fenugreek 
- Leek or cabbage 
- Beets 
- Dates
- Gourd
- Pomegranate  
- Fish  
- Head of a fish 
When eating the simanim the proper prayer should be said prior to eating (Artscroll Machzor, pages 96-98). There is a difference of opinion as to whether it is the eating of these simanim or the accompanying prayer which is the essence. The simanim are another way of beseeching God’s blessing for a sweet year full of opportunity for growth and accomplishment. There is a custom not to eat nuts on Rosh Hashana. 

New Fruit: One should have a new fruit on the second night of Rosh Hashana. The fruit should be present during candle lighting and kiddush when the bracha of shehecheyanu is recited.  

Shofar: One should preferably be in Shul to hear all 100 blasts of the shofar. If one is not able to be in shul for all 100 blasts, one can fulfill his/her obligation to hear the shofar by hearing the first 30 blasts which are blown immediately following the blessings. Women who are caring for young children can fulfill their obligation with the initial 30 blasts.  

Tashlich: After mincha on the first day of Rosh Hashana, one should go to a body of water to say the tefilla of Tashlich; in which we symbolically cast away our sins in an effort to cleanse and start again. We will be reciting Tashlich following Mincha on first day of Rosh Hashana.  

Napping: Many have the custom to avoid napping on Rosh Hashana. We must make sure to maximize the power of this sacred day. 

Seudos: The mitzva of v’samachta b’chagecha (to rejoice on Yom Tov) applies on Rosh Hashana just like any other Yom Tov. Therefore, one should make sure to have two seudos (meals) each day of Rosh Hashana. Yaale V’yavo is said in Birkas HaMazon, although Birkas HaMazon is not repeated if Yaale V’yavo is forgotten.  

Aseres Yimaei T’shuva (10 Days of Repentance): 
Insertions in Teffilos: The following insertions or changes are made to the Shemona Esrei prayer beginning with Rosh Hashana: 
- In the bracha of Ata Kadosh we say Hamelech Hakadosh instead of Ha’el Hakadosh. If one forgot the change, or is unsure if he remembered the change, he must repeat the amida.  
- In the bracha of Hashiva Shofteinu, we end with Hamelech Hakadosh instead of "Melech ohev tzedaka umishpat". If one used the regular conclusion to the bracha he does not repeat.  
- There are four other insertions made throughout the amida, they are: zachreinu l’chaim, mi chamocha, u’chsov and besefer chaim. If these insertions are forgotten, the amida is not repeated.  

General conduct and stringencies: It is appropriate to be more attentive to our general conduct during the period between Rosh Hashana and Yom Kippur. This includes general conduct such as our personal relationship with Hashem, as well as our interpersonal relationships. There are some who accept added halachic stringencies upon themselves during this time, such as consuming only Chalav Yisroel and Pas Yisroel.  In this same vein, we must be exceptionally meticulous in our interpersonal relationships, exerting great attentiveness in how we talk, treat others and conduct ourselves.