Can’t talk about this trick enough times.

I thought I knew this trick until you got to the depth part 😳 Thank you for this 🙏

Thank you, that’s the part I never see in tutorials! What good is just a line? It needs depth. It also works for evenly spaced windows on a wall, columns, streets on a ground plane grid, you name it.

And the fun thing is that it works even better in spherical perspective. That's basically how I did this one, if you take the columns to be the rail boards. I say it works even better because the vanishing points are always inside the picture in spherical perspective.

Maybe I'm overthinking this, but when you say the first one didn't matter, is that that like deciding the focal length? Is there a "natural" width when you're trying to draw a square in perspective?

Yes, that’s right. The distance between the first two is arbitrary because of focal length—basically, how close the viewer is to the subject, and how much of the field of view you want the subject to occupy.

I was introduced to this technique through a (now free) book called Perspective Made Easy, by Ernest Norling. It takes less than an hour to read and it will definitely up anyone's skill!

More subdivision techniques here. Fast and useful:

Very good. :) I always get grumpy when I see tutorials screw up the railroad trick - it dates all the way back to Alberti, it is a thing of beauty. :) You did that neatly.

One of the most useful tricks I saw in Scott Robertson's How to Draw, ahah. I'd bet you're familiar with the book too!