1. Focusing on food, to the extent that people begin to worry about eating more than actually fasting. This also goes along with spending heaps of money on iftars even though a person does not need to eat that much food.
2. Making sahoor much before Fajr. Eating sahoor a few hours after Tarawih or Isha prayer is wrong. It should be taken closer to the time of Fajr.
3. There’re people who don’t make niyyah (intention) for fast, as they think this is something. which is in heart and one doesn’t need to be verbal. They also think the intention needs to be made once at the beginning of Ramadan and not every single day, which is wrong.
4. If you find out late that Ramadan has started, you should stop eating and fast for that day, making that day up after Ramadan/Eid ends.
5. About Tarawih, some think that it is not prayed on the first night of Ramadan, believing it should be started after the first day of fasting. They forget that the Islamic calendar runs on the moon, Maghrib is the start of the new day.
6. Many people believe if you eat or drink by mistake this breaks your fast. This is false. If you happen to eat or drink by mistake then you continue fasting and do not need to make up for the day.
7. Some people are of the opinion that if they see someone eating or drinking they should not remind the person that he/she is fasting. According to Sheikh bin Baaz, this is incorrect and it is an order from Allah for us to ordain the good and forbid the evil. Thus we tell the person, because we are forbidding the evil this way.
8. Many sisters believe they cannot use henna while fasting. This is incorrect; they are allowed to use it during Ramadan.
9. Some people believe when you are cooking you cannot taste the food to see if it has the right spices/flavors. This is false, it is allowed in Islam as long as the person cooking is not eating the food. Rather they can taste it to see if it needs salt, or more spices.
10. Many people think you cannot use a miswak or toothbrush during Ramadan. This is false, for the Prophet (peace be upon him) would use miswak during Ramadan. Also you can use toothpaste; the reasoning by the scholars is that the miswak has flavor, thus toothpaste is okay to use [if you are not eating it].
11. Some people make the Fajr adhan early. They do this so people will stop eating before Fajr and not invalidate their fast. This is wrong and something we should not do.
12. Some people make the Maghrib adhan late. They do this so that people will start eating late, just in case Maghrib has not come in yet. This too is wrong and we should refrain from such practices.
13. Many believe sleeping with spouse during the whole month of Ramadan is forbidden. This is false, you cannot do this only during the times when you are fasting. Between Maghrib and Fajr it is permissible to do.
14. Many women believe that if their period has just ended and they did not make ghusl, they cannot fast that day (considering their period ended at night, and they went to bed without ghusl, waking up without having a chance to make it). This is incorrect, if a women has not made ghusl she can still fast.
15. Many men believe that if he has had intercourse with his wife and did not make ghusl (similar to the above) then he cannot fast the next morning. This is also incorrect, for he can fast even if he has not made ghusl.
16. Some people pray Dhur and Asr prayers together during Ramadan. This is incorrect and should be avoided.
17. Some people believe you cannot eat until the muezzin is done calling the Maghrib adhan. This is incorrect, as soon as he starts a person can break their fast.
18. Many people don’t take advantage of making d’ua before they break their fast. This is one of the three times when Allah accepts a person d’ua.
19. Many people make the mistake of spending the later part of Ramadan preparing for Eid, neglecting Ramadan. This is incorrect and these people lose the concept of what Ramadan is about.
20. Many parents do not let their children fast during Ramadan (young children). This is something counter productive to a child. By allowing him to fast he will grow up to know he must do this act.
21. Some people think Ramadan is just about refraining from eating and that it is nothing to do with one’s behavior. In fact we are supposed to control our tempers and badmouthing more during Ramadan.
22. People often waste their time. They tend to sleep the whole day and doing nothing. Ramadan however provides us opportunity to take advantage of this blessed month by doing more Ibadah.
23. Some people travel much during in this month thinking they will have to break their fast while traveling. This is in fact optional. If someone wants to break fast while traveling one can (with making it up later), otherwise one can continue fasting.
24. Many people who are able don’t make i’tikaf in the masjid. We should take advantage of our good health and spend lots of time inside masjid, especially during the last 10 days of Ramadan.
25. Some people believe they cannot cut their hair or nails during Ramadan. This is also false.
26. Some say you cannot swallow your spit during Ramadan. This too is false. However you cannot swallow mucus that has entered your mouth.
27. Some say you cannot use scented oils or perfumes during Ramadan. This too is false.
28. The belief that bleeding breaks the fast is not true.
29. Some believe fast is broken if one gets hurt. This is not true.
30. Putting water inside nose and mouth during wudu would break fast is another wrong perception.
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Courtesy of ummah.com