Acts contrary to the meaning and purpose of the fast,  which might even break the fast if done excessively, are the makruh acts of fasting. Tasting or chewing, for example, are makruh because the possibility of swallowing it. Although it does not break the fast, treatments that weaken the body - like giving blood - are makruh while fasting. (Ilmihal, 406) The fasting person should avoid anything that could cause harm to the meaning of the fast.

Some acts are recommended if one wants to experience the spiritual atmosphere of Ramadan and taste the sweetness of the fast. Despite having no direct effect on the validity of the fast, the Prophet advised us to perform recommended acts as to attain a better experience and adorn our worship. Muslims have adopted certain types of etiquette and the recommended and Sunnah acts into their daily lives and made them a part of their cultural tradition. 

Of all the actions that help us taste the sweetness of fasting, waking up for the sahur meal comes first. By waking up before dawn and eating the sahur meal even if but a little, one will attain the blessings and merits of the early morning. In order to benefit from the time of forgiveness and supplication, one should have the sahur meal in the last third of the night as to combine the blessing of the morning with the duas and tahajjud  prayers of the night. 

It is recommended to break the fast as soon as the sun sets. The Prophet of Allah said concerning the break of the fast: “As long as people break their fast on time, they will remain upon goodness.”(Bukhari, Sawm, 45) 

The other commended acts of the fast include: supplicating before the fast ends, breaking the fast with water or something sweet like a date, performing the major ablution (ghusl) -if required- before dawn, increasing charity and benevolence to your kin, close ones and the needy, abstaining from foul words and actions; focusing on prayer, Tilawah (Qur'an recitation), supplication, sending salutations and blessings and similar forms of worship and performing the Itikaf during the last ten days of Ramadan. (İbrahim Kâfi Dönmez, “Oruç”, DİA, XXXIII, 416-425, İlmihal, 402-403))