Magic: The Delicioso spell can conjure a single plate of somewhat random food (the selection is fairly limited) but it can also be used to refresh food that has gone bad, including food that should not have gone bad like cookies.
Get famous: Selling paintings from the inventory does not give fame points, selling them from a wall or from the easel does. Using the Digital Sketchpad instead of an easel means the paintings go straight in the inventory, so if you want fame, drag them to a wall first. (My experience so far is that fame is not worth it because of the quirks.) If you do want fame, Digital Sketchpad is still the way to go, since you can make more paintings in a shorter time and also can queue them up before you start.
Sickness: Even if you cure a sim with medicine, they may already have passed it on to other family members, who will then infect the first patient once the medicine moodlet wears off. But if you give medicine to sims who are not sick, they will get a dazed moodlet instead of the energized. If only there was a way to find out who was sick even if they did not show symptoms at the moment... Try to let the whole family drink orange juice. Those who have the cold will get a cross moodlet "combating a cold with home remedies". You can now cure them with medicine.