Estimating in SCRUM

Lately I received this question while I was working with agile teams:

What's the best way to estimate the backlog for an agile team in my opinion?

And always I am saying that the estimation should be made by the people who are doing the work. A common tactic used by scrum teams is to estimate using a unit of measurement referred to as the Story Point.

Here you can find more details about the estimation https://www.iadvised.com/estimating-in-scrum