A friend's wife started an at home high end custom chocolates business. Mixes her own chocolates, uses a variety of forms to pre-form the objects, adds customizations to create her unique brand and takes customer specific requests. Corporations and private sector businesses order them for employee recognition, people order for life's various celebrations, some local stores carry her more generic, seasonal chocolates. She does small batches, has had to turn away high volume business opportunities because she doesn't want to grow that big. She's been operating ~15 years.

Buying and selling on eBay, Facebook market, 2econdhand, Vinted, etc

You can start at your rhythm. You can specialize in a niche or multiple niche or you can be a generalist and find what you like more. If you have a lot of space to fill you can start to buy car parts and even broken-down trucks/cars for parts. Kitchen appliances and parts. Or you can store furnitures.

The key is in the ads you will make. A lot of photos. Taking care of the staging of your photos. Long descriptions. People love to read about what they are interested in. Being on time, making clear appointments, responding quickly, proposing shipping, etc etc. It's possible to make some money like that but not to get rich.

depends on how they're manufactured. I have a lightweight cnc that's good for balsa wood and acrylic more or less, 3d printer, laser engraving attachment and more shit. It doesn't make me rich but i do sell things. They've all paid for themselves outside of the 3d printer atm. There's also a basement full of immigrants, that's another manufacturing strategy. But I can't afford that. Legally.

CNC router, machine lathe and a milling machine are the three critical base line pieces of equipment you need to build almost anything else.

Sinks, countertops! There are fake marble countertops and sinks. If you take your time and try you can make some beautiful "marble" countertops. You get the molds you want to make and the material to make them. Find a few stores to carry your product and off you go! I missed out on buying a whole outfit with an established clientele back in the 1990's. I found out about it a week after he sold it.

You absolutely cannot compete with China on cost or even quality. You can only compete with them on your narrative. Have a story to tell, tell it on youtube and social media, then maybe you can find a market.

My friend's business started just a few years ago and now it has 100+ employees and does millions in business per year. They are co-located with a metal shop. Despite this, they buy their strips of metal from China. China does it better and cheaper than the shop that is literally in the same room with them.

How does my friend's business do so well? Narrative. They target a specific market and have a fairly popular youtube channel. They are selling a story, an experience. They also created their market, so they have first-mover advantage and are bigger than all of their competitors combined.

I would consider finding a niche manufacturing business, the kind that is for sale because "my kids don't want it".

I used to do business with a guy whose whole business was drilling deep tight tolerance bores on aero/space hardware. He made good money, had more work than he could handle and didn't have to leave his house. His kids didn't want the business, even though he had already made a few million.

In regards to a business model for manufacturing things for sale w/ greatest return of investment w/ out much knowledge or initial cost, I would say soap, candles, & coffee bean roasting (need food handling licensing for this one).

I've been making wallets lately and just getting into boots. A bit more expensive in terms of purchasing all your molds & tools but a great return if your product is of high quality. If you look into Nick's boots or White's boots, their products are of the best quality & are often paid for through uniform allowances from linemen, & firefighters. Some of their most popular models are upwards of $500 (US) https://nicksboots.com/ https://whitesboots.com/

Discontinued car parts.

Anything with a raspberry pi