I just use a piece of acrylic.
If you wanted to go the extra then you would heat the acrylic and make a bend at the end so that end acts as a foot for use on a hard surface. And make a cutaway at the top to match the curve of the crank arm/bottom bracket interface.
And then you should have a number to accommodate differing bottom bracket heights.
And easier to photograph on a cloudy day.

I now don't bother to Photoshop it out, and it is clear in this photo. It is a very simple task in Photoshop to clone adjacent grass to match.
But then if it is removed, it is confusing to the eye and that, to me is taking away from looking at the image. You also wonder what other 'corrections' were done. That then lessens the presentation.
For me, it is better for someone who wants to know to see the answer, appreciate the care taken and then return to the image.

I do not like the garage doors or other distractions that inevitably come from propping it up against an object.

Pursuit side by philip.knight, on Flickr

And then you can get back to the real purpose of looking at what someone posts as a finished project. All the things you would do to finish it properly.