There is no religious base for fasting to welcome and see off Ramadan. However, the Prophet used to fast many times in the month of Sha’ban and six days in the month of Shawwal. It is makrooh to fast for one or two days previously as a precaution considering that Ramadan has already begun even if it has not. However, it is not wrong for the ones who have made fasting as a habit on certain days to fast if their certain days coincide with these days. Likewise, the Prophet (pbuh) said “Do not welcome Ramadan with fasting for one or two days before it. But if a person spends these days fasting as a habit, they should keep on this.” (Bukhari, Fasting, 14; Muslim, Fasting, 21)