I'm currently half of the way through 250 box challenge and I have been facing a problem from the start of this drawabox journey. Adjusting the exercise to my failures. After I make a mistake while doing a line that is meant to be the foundation for the next step, I don't know what to do. Drawabox advice is:

• Don't repeat an exercise only because it's wrong because it's a practice not a final product.

• Keep going forward to avoid the grind (and try your best to learn from your mistakes).

But the thing is: Can I go forward? How I am supposed to draw a 4 side figure if i messed up so badly that the first 3 lines made a triangle before placing the last line? Maybe this is too exaggerating but the point I want to make is that after some mistakes, the exercise loses a lot of it's value and I don't know what is the best way to circunvent this.

The 2 options I have think about are keep with the drawn or keep with the planned. Any additional option is appreciated.

I have made a quick picture to visualize the following example better https://imgur.com/a/TcgKrQX

Let's say we are drawing a box for the 250 box challenge. We place our 3 starting points and start joining the dots together. One of those lines goes wrong a bit, should we use the end of that line for the rest of the exercise or ignore it and use our reference dot? After drawing that line we start to plan our next step, so we place the following 3 corners but after ghosting a lot to avoid it, we still fail again and our line goes wrong in the final stroke. Should we use that line or stay with the reference point we placed? Should we try to draw over it if one of our lines is not long enough to reach the reference point?

There are moments along the exercise where, if an important line goes wrong, the exercise can't be completed with the same purpose it was made for. In the box exercise, failing on the execution means all the lines you planned well now will fail meeting at the same point after extending them to the vanishing point.