I'm going to share something here.
Keep in mind I spent the majority of my life building houses. My most used language is "concrete", "2X4" and "ouch, that hurts".
So if I can figure out how to do this, you whiz kids certainly can.
I can not emphasize enough the importance of getting a really simple photo editing program.
I am still using the photo editing program that came with my first Gateway computer 15 years ago.
The very same program. No longer made - but really simple.
Those light tents mentioned above are really nice for getting some pictures of the knife as they diffuse the lighting and eliminate shadows. Just a few small lights around the tent and all the shadows are gone.
With my editing program, I take that knife and make a cut-out of it and with the click of a button place it on top of any photo I want. Anything.
Then, I add a shadow - or not.
This first photo is a picture of a ditch in the woods by my house.
I placed a cut-out of a knife on top of it with no other editing.
The pictures of these knives were taken with a little cannon point-and-shoot that cost maybe 100 bucks.
Now, this next picture is one I stole off the internet by doing a search for 'photo background'.
Then, I placed a cutout on it with no other editing:
Then, with the click of a button I add a shadow:
And then, with a little "slider" control I soften the edge of the shadow:
That's how I did this knife on a picture of a piece of birch bark. It shows both sides of the knife - right? So, it can't ACTUALLY be laying on the birch bark.
That's how I do some of my photography.
All that said, I do like the appearance of natural lighting, but when I live where the temp might be sub-zero for 2-3 months, outside photography is not an option.