Working from home is WORK -- it's essential that people understand that. There is nothing "easy" about it, unfortunately.
Selling items on eBay is fine if you have stuff to sell, but once it's gone, it's gone. Same thing for selling your jewelry - it's a one-time payment, and once you're out of inventory, the money stops coming in. I have an acquaintance who sells on eBay for other people, but he spends a lot of time with things listed waiting for bids, and then he has the hassle of packing and shipping. It takes a while to be known as a power seller who is trusted and to get other people to let you sell their things on their behalf, if that's what you are thinking of.
You don't say if you have any special skills or experience that would paly a role here, so it's hard to answer you specifically.
If you have to lay out a lot of money to join an organization or buy a lot of materials, it's probably not legitimate.
The biggest growth in business is direct sales. It's one of the fields projected to continue to grow. There are ways to check out direct selling companies for legitimacy: membership in the Direct Selling Association is essential. That's by invitation only, and after a full year of scrutiny and examination of books, interviews with current and former distributors, analysis of the compensation plan, etc. Only about 200 of the 5000+ direct selling companies agree to be evaluated and then actually measure up. See whose executives are asked to serve on the DSA Board of Directors too. That lets you know that they are well regarded for integrity and honesty.
If you get into direct sales, be sure it is a consumable product so that people order continuously, not just for occasional household purchases or holiday gift-giving. Be sure there is free and ongoing training (ideally something you can attend ahead of time to check it out), and a non-competitive support system as well. Be sure that your market is more than just your friends and relatives - otherwise you will not have ongoing income. Look for residual income too with a strong compensation program. Be sure you don't have to invest in a lot of inventory, and that there is a business guarantee.
I work from home for a company with 25 years of exemplary performance. Some people do it part-time around other jobs, some do it full-time, and some work their way into full-time so they can quit their current jobs. But it's work. I set my own schedule, but if there's nothing in my planner, there's nothing in my paycheck. So be sure you are a self-starter and that you are not too distracted with other things or too tired from your other job. I had no special abilities in this field, but I get ongoing and free training, both on line and in small and large group settings. But I have to put in the time.