It is OK to use tools to get it right.
For some reason many people feel guilty if they use tools to help them sketch, but artists from Da Vince, to Van Gogh, and beyond have taken advantage of various things to help. One of the most frequent tools is a grid viewfinder.
Here is a sketch that Van Gogh made of the large wooden grid he would carry with him into the field. He drove the stakes into the ground, then viewed his scene through the grid. His is specifically designed to help with perspective.

Da Vinci’s use of a grid is so famous that there is even a branded viewfinder that is quite helpful.


I have an app on my phone that produces a grid from a photo you snap.

Here is one I did at the Tuileries in Paris.

Next week I will add a couple more. Sketching is supposed to be fun, and if a tool or two makes it easier then that is a good thing.
Enjoy trying something new.