Accurately apply seed in flowerpot

I would like to reap carrots on my balcony garden this year and ordered seed of a blood red variety. Since I did not just want to accommodate the already limited number of seeds indiscriminately in the pot, I have considered how I can do this most meaningfully and have considered the following:

Why not dig into the earth with plastic bowls of different sizes, which each of us has en masse? For this I have brought my flower pot in the kitchen and selected by eye three bowls, which I then successively pressed carefully into the previously beautifully leveled soil.

And voilá: Perfectly drawn Saatrillen! Of course, also works with square tubs and square bowls?