Try looking for products with the following attributes:
surprise factor
not found in store
mass market appeal
problem solved
Seems to be of high quality (margin)
Good marketability (lifestyle pictures and videos)
Last year unscaled (saturated)
You can use product research tools like DropPoint, Ecomhunt, Bigspy, or pay someone on Fiverr to do it for you (not recommended if you're on a low budget).
Overall, you will have to browse a lot of different products, and there is no easy way to get around it. It is better to spend time looking for a good product than to spend money promoting a bad product. Finding a good product to test will actually save you money in the end because it won't be wasted on a poor quality product.
Once you find a good product, make sure the supplier is good and make sure the shipping includes a tracking number, https://www.larnt.com/product-home?q=s supplier I use is pretty good.
Hope this helps