Levelling can be done by levelling process on the machine where you move a card in between the nozzle and build platform, but sometimes the 'tug' of the card can vary and you won't get an as reliable result.

One way that seems to work well is printing a model that extends to the four corners, like this one. You can observe how it is printing and turn the dials.

Thinner line = platform needs to move up = turn clockwise

Too thick line / almost transperent / scratching the build platform (tape) = platform needs to move down = turn counter clockwise

It's a good idea to level the build platform before the first print of a day. As well as before a long print. Make sure there are no curls in the tape, as that could cause some problems with the print.