There are two ways to execute Super Arts...
1.) You can charge a special attack that shares the Super Art input, thus resulting in a Super Art. An example of this is Ryu having a Super Art that shares the same input as his Hadouken. You can do the quarter circle forward and hold the punch and it will charge, flashing once for an ex and then releasing a Super Art after another second or two. This is by far the faster method as it requires no meter.
2.) You can expend two bars and simply do the input for the varying Super Arts. This method is much slower and should only be used while doing Pandoras or when the situation allows it.
I personally set up with two players and simply spammed Ryu's charged hadoukens for one round on opponents with minimal bars. This nets you the 300 wins, then you change it to full health bars and keep spamming them for 500 connections. It's worth noting they must hit, if they are blocked or evaded they don't count.