What are the reprehensible acts (makroohaat), innovations (bida'), and recommended acts (mustahabbaat) in obligatory and voluntary fasting? And is kohl an innovation in fasting or otherwise?

It is Sunnah for the fasting person to delay the pre-dawn meal (suhoor) unless they fear the rise of dawn, and to hasten breaking the fast (iftar) once sunset is confirmed, based on the Prophet's (peace be upon him) saying: "Hasten breaking the fast and delay the pre-dawn meal." It is also Sunnah for someone who is insulted to say: "I am fasting." It is Sunnah for one to break their fast with fresh dates (rutab), and if not available, then with dry dates (tamr), otherwise with water. It is Sunnah at the time of breaking the fast to say: "O Allah, for You I have fasted and with Your provision I have broken my fast. Thirst has gone, the veins are moistened, and the reward is confirmed, if Allah wills."