PCB Routing Tips?

oric_dan(333):
They always look ugly, with more than a couple of traces. However, you should look
at the top and bottom trace layers separately to get a better idea of how the layout
went. Also, the most obvious problem with auto-routing, the way you did it, is that
the power and ground traces are not nice and fat [ie, 30-50 mils], like they should
normally be to handle non-trivial currents.

So I should change the width to 50 mil and then click on each power and gnd trace? Is there a quick way to change them all at one time?