Get-rich-quick schemes and fad weight-loss diets are naturally popular because they satisfy the id while also attending to the super-ego. The ego's job is complete when it sees something like this. The appeal of "fast'' stems from the innate desire for instant gratification, so beware of what seems too good to be true (they often are) when you're looking to make money quickly. Be wary. Listen to the conversation deep within the confines of your mind and do your best to tame the proverbial beasts.
Drive for Uber or Lyft: If you're in a locale where you can find Uber or Lyft (or even one of the many competitors around the world such as China's Didi), you could easily make a respectable income. The hours are flexible and you can work as you see fit, making it perfect even if you currently have full-time employment but are looking to make some money on the side.
Using a food delivery service can’t necessarily earn you money, but it can help you save you money if you constantly find yourself throwing out half the food you buy. Food delivery services send a box of food every week with new, sometimes unique vegetables, meat, fruit, and so on. If you don’t have time to shop and want simple meal-prep that leads to a good meal, a food subscription service may be perfect for you.