I'm given a description of a regular language $L$, and I have a candidate regular expression. Is there a systematic, step-by-step way to test whether the candidate regular expression is correct?

I know that there can be multiple regular expressions that are correct.

^{This is intended as a reference we can point others to. Please explain your method in a form that someone new can understand it.}

I'm given a description of a regular language $L$, and I have a candidate regular expression $R$. Is there a systematic, step-by-step way to test whether the candidate regular expression is correct?

I know that there can be multiple regular expressions that are correct.

^{This is intended as a reference we can point others to. Please explain your method in a form that someone new can understand it.}