Photoshop 3D is an amazing tool which you can use to create many items using .png formatted images with a transparent background.
I obtain my images from Google Advanced Image Search.
Google Advanced search is the first choice when I select my images. The page has various selections for just exactly you are searching for, even commercially. This is the safest way to obtain legal images for use of publishing or selling your finished piece. Always making sure of the CC0 public domain images.
Another great resource I use is Pixabay, these are free for use - even commercially.
I wanted to create seashells so I found this great .png formatted image using the Google Advanced Image Search.
It said .png format but it wasn’t transparent background – it had a grid background, so I had to edit it and delete background so that the image had a transparent background and also the little holes in the sand dollar had to also be deleted. You need the background to be transparent to avoid these extra steps of cleaning up the image.
You can make shells or flowers for your hair this way. When you search for your images, grab a few different .png formatted images and make a file of them for later use, this saves lots of time and will keep you inspired to create the next shell or flower. Always keep a note card of where you took your images from, so if you are questioned about the use of a said image you have proof you are not infringing on rights. I keep a note in the file where my models are.
Now that we have our images let’s begin our lesson.
Open your sand dollar to your Photoshop desktop as seen in the image above.
On the right of your screen, you will see Properties Panel and down in the middle area you will see the 3d-Layer-Channel choices, make sure it is set to the 3D choice. With 3D choice selected  make sure your 3D Extrusion is selected.
Then 2-> Select Create
You will get something like this image seen below.
This is great! But, it is not exactly the shape we are seeking. If you select your sand dollar, to the right on your Properties Panel you will see a blue Shape Preset window. As seen in the image below.
Now, if you select the down arrow in the drop down menu, you will see various shape presets that you choose to change your shape. You can also set the extrusion depth. A sand dollar is not too thick so you would find the poofy shape preset I call it, click the down arrow and choose the sixth selection of the menu on the right. I use it for everything even my hair flowers. It gives it just enough poof to look real.
After you select the preset your sand dollar will look like the image below.
Now for saving and bringing in-world. On the top of your desktop-the toolbar-top of your screen, you will see File>Edit>Image>Layer>Type>Select>Filter and finally 3D select 3D and the drop down you will want to select Export 3D Layer and save the sand dollar as a .dae file to your hard drive for uploading in-world.
You can create an endless number of items like this. I made, a crab, steaks and bacon even, those were probably the first I tried! Try everything the results depend on the image and the “Shape Preset” you choose.
The last step would be to grab the original texture for texturing in-world, for me it is faster than unwrapping etc. the result is not much difference with the shells and flowers. Just edit it and apply texture and adjust to fit model.
Software has become simply amazing. Get out there and try it!