Best way to get from Gare du Nord to Rue Cler?

Best? Least expensive? It's all relative. How many people? Taking a taxi would be the easiest.

The métro will not be particularly convenient, particularly to addresses along the north end of rue Cler. Bus line 42 does not really go near rue Cler and buses in general can be awkward for those with luggage.

Taxi is the only option I would consider. Be sure to go to the official taxi queue located on the west side of Gare du Nord, near the Eurostar platform. Do not accept offers from rouge drivers soliciting from within or in front of the station.

This is just the situation where we take a taxi: to and from our hotel if it is not within walking distance. We have done the exact same trek from Gare du Nord to Rue Cler and it is worth the €25.00. Just queue outside Gare du Nord with others arriving. It moves quite quickly.

Thank you so much! Just what we needed to know?

Before you leave Gard du Nord, take a few minutes and buy some metro/bus tickets so that you have them on hand for later.