Product photography is an independent and broad field of photography so if you want to achieve profesional results you should invest in learning how to do it, a camera that can control an external flash and couple of flashes with umbrellas and tripod.... or pay someone who knows and have the equipment to do it.
However, you may try two tricks and could be good enough for a small online shop:
1st: Take your products to your local printing / xerox shop and ask the clerk to scan them. Depending on the size of the product and the width it can render very nice results with soft and uniform light and strong defocus towards a black background. Google it to see samples.
2nd: Get a flashlight that gives you a white light. Any cheap one works, just try to get one that has white light like a the ones with a led bulb. Download a camera app for your iphone that allows you to take slow shuter pictures, meaning pictures that last for at least 5 sec. Check in the app store, there are plenty of them that are free.
Place your phone over something that holds it on the top while your product is on the bottom so you dont hold the iphone with your hands, like a shoebox or the border of a table, being your phone at the edge of the table with the camera over it and the product in the floor.
Then turn off the light of the room and be sure to be in darkness.
Set the exposure in the camera app at 5 sec, press the shoot button and turn on your flashlight and move it during the 5 sec over the top and sides of your product. Move your flashlight all the time around the product.
Experiment with different shutter speed setting, try lighting the product from different angles and distances from the flashlight to the product.
This is a field of photography named flashpainting and it is fun, so enjoy it!!
Good luck and... share samples of the pics! :)
;-)
– Toby Speight Oct 17 '18 at 13:32