If you are good with a computer…
Make return address labels and sell them for a set price (i.e. $5.00-$10.00 for 100 labels). Check local office supply stores to find sheets of blank labels or find them online. This can be very effective around Christmas card time; especially if you have a color printer. Also be sure to be careful in your calculations as printer ink costs a significant amount of money. Make colorful signs to advertise or create a PDF example of the different design options you will offer to email to interested people. Take orders for the labels, make and print the labels as soon as you get the order, if possible. Collect the money when the order is placed or when you deliver the labels.