Use your credit card’s cash advance feature. Some credit cards will allow you to withdraw a certain amount of cash by using it at an ATM. This can help you come up with cash in a hurry. However, the interest rates on cash advances are usually much higher than the credit card’s usual interest rate, meaning that you will eventually have to pay more.
Harvesting cursed energy is a very easy skilling money-making method that allows you to make over 3 million gold per hour while also training your divination skill in the process. This method takes place in the wilderness at the wilderness volcano so be ware of PKers and people trying to kill you. All you need to do is collect the cursed whisps in the crater and deposit them into the center of the crater to gather cursed energy. You will, however, need to sell this energy to other players, not the grand exchange, to make a profit. A more detailed guide can be found in the video linked below.
Try night filling for supermarkets/large stores, supermarket/retail cashiers, vacation seasonal factory work/seasonal fruit picking, night reception in a small hotel, cleaning, gas station attendant, making crafts or artwork and selling online, YouTube video making (but it needs to be popular), dog walking, babysitting, tutoring, housesitting, etc. There are many part-time options where college students are favored because people get to pay you less than a service provider but get to know you better, so it's a friendlier arrangement.
Become a babysitter if you are good with children. There are websites that will connect you with people who need a babysitter. To get hired by people who do not know you, it will help to pass a CPR class, or to have a special talent or expertise for entertaining children. However, you might be able to make money more quickly just by babysitting for people you know, or by having friends refer you to others who need a babysitter.