• Excessive spitting to avoid swallowing saliva 

• Not entering water into the nose (sniffing) during ablution and merely washing the tip of the nose.  

A person is required not to draw the water deep into the nose while sniffing if he is fasting, but one is not to violate the act of ablution by leaving it out altogether either. The Prophet, , said: "Exaggerate while sniffing unless you are fasting." Imaam As-San'aani said, "The narration is evidence to exaggerate the sniffing when not fasting. Exaggeration is forbidden when fasting in case something comes down the throat and nullifies the fast."

• Feeling guilty when waking up in Janabah (state of sexual defilement)
   

A fasting person may feel guilty if they wake up in a state of Janabah, even though there is no need to feel this way and it is permissible to complete their fast despite this. In fact, at times, the Prophet, , used to be in the state of Janabah at dawn during Ramadan, and he would take a bath and fast.

Shaykh Abdul-'Azeez Ibn Baaz was asked if a fasting person has a wet dream in the morning during Ramadan, does it nullify the fast and does the person have to take a bath? He replied that wet dreams do not nullify the fast because they are an involuntary act and that a bath is necessary if semen is secreted. It is acceptable to delay the washing until Thuhr (afternoon) prayer if the wet dream occurred after Fajr (dawn prayer).

The same goes for Janabah; you can take a bath after dawn if it occurred at night because it was proven that the Prophet, , used to wake up in a state of Janabah then wash and fast. It is better to wash from Janabah before Fajr prayer in order to be able to pray in congregation.
 

• Reluctance to taste the food while cooking for fear of nullifying the fast.
   

There is nothing that warrants this reluctance as long as no food is swallowed. Ibn 'Abbaas, may Allah be pleased with him, said, "There is no harm in tasting the food." [Al-Bukhari]. Shaykh 'Abdullaah Ibn Jibreen was asked, "Can a cook, while fasting, taste the food being cooked to make sure it is good?" He replied, "It is acceptable to taste the food when necessary by placing it at the tip of the tongue to see if it is sweet, salty or the like. Nothing should be swallowed, but it should be spit out. This will not nullify the fast."