My best advice is to use a more friendly background that you prefer when taking the photo. This way you won't need to make post changes.
But for this image, isolate/select the BG and add a Gaussian Blur.
Duplicate your image and convert into a smart object.
Apply a smart Gaussian Blur filter.
Use the layer mask generated by the SO to mask out the parts that you don't want to be blurry. View attachment 126836 View attachment 126837
Thanks for the reply and your time
I just remembered that I asked another photographer that takes flat lay photos, and she told me she replace the whole background after taking the photos. How can I do that and remain / create non grainy shadows..?
I'm not the guy to necessarily follow but here's what I did -
Selected and placed the pretzel and salt pieces on another layer
On the layer below, use content aware fill to eliminate the pretzel and salt pieces and make background uniform
Applied a gaussian blur to the background layer
On the pretzel/salt pieces layer, I applied a drop shadow
I used a layer to mask out the salt shadows so it matches your original image
There are other more creative ways to add shadows...