On my Sx700 I use the assignable buttons ...

I assign one of the buttons to "REGISTRATION BANK INFORMATION"
then I can easily just hit that assignable button and the reg menu opens up listing all the songs in a list for that bank.......
then I can use the REG buttons + or- to go thru the Pages of songs 8 songs per page....

As far as what songs to pick I just look at the audiences and choose what ever I feel is needed to have a great show. No play list ever...every show is different..