You could become bonded and put the word out that you are available for house, plant, and/or pet sitting for people who go out of town. Picking up their paper and mail, turning lights on at night, feed the fish, let the dog out twice a day,.... etc. It's hard to find trustworthy people to do those things. Ask friends to refer you and to advertise on their bulletin board at work.
A friend of mine goes to yard sales and thrift shops, browsing for things that she knows sell well on e-bay. She says that new, name brand children's clothing and antiques are a good gamble. ( If you come across any OLD WTS literature, it can be kind of pricey. I know! I have paid a tidy little sum for the treasures myself! Especially the ones that prove false prophecies and changed teachings. ) Just make sure you make it worth your while on the shipping.
Holiday time is a good time to advertise baked products. I know a lady who makes a killing on her yeast rolls and Christmas cookies. Another girl makes candles and I was amazed at the amount of orders she received.
My niece makes a nice additional income from the jars of cookie mixes and soups that she layers into pretty little gifts. They are labeled with the "how to fix" instructions & have a fancy little bow. She takes orders and people she works with buy them up like hot cakes. Last minute gifts. A good bet this time of year. Don't cost much to make, Yet, are worth a lot to someone who is in a crunch for time.
Long term, it takes a while to build up a good client list. You have to build a reputation and trust. Word of mouth is the best way. The girl who made the candles handed me and all her other friends a list of the scents and sizes, prices, and asked us to see if our friends would like to order. I was amazed! I reluctantly asked around, and EVERYONE was interested! She expanded to include soaps, lotions, and shampoos. She used regular canning jars for her candles. Cheap from the dollar store.
Find what you enjoy, then advertise on bulletin boards (in grocery stores, churches, etc...) , small town newspapers, club newsletters, college newspapers, etc... Anywhere that is cheap. Try to keep your over-head low and your quality nice. Don't under price yourself. I did that with my small business, then it was a headache to try to raise the prices. Everyone expects it to stay the same. You want to be competitive, but keep it worth your while. Otherwise, you will get burnt out.
A lot of home based businesses work around seasons. Lawn mowing in the summer, snow removal in the winter. It goes in waves. Find what you like and go for it! It pans out for a lot of people.