Were used in order to provide spaces through which weapons could be fired at invading enemies during medieval times

Crenellations

Explanation:

the first thing you will need is patience a simple drawing can take 2 years the more time the better, you will start by copying some drawings and when you get better at it you can start doing your own drawings. when your drawing you need to be super patient. even proffessionals learn new things all the time. i hope this advice .