And it's been one year me doing Puppet-making and puppeteering.  Yup.  I need anyone's help with one thing.  As I do two puppets, I am doing the voice of puppet 1.  I switch to puppet 2 and do the voice of puppet 1.  I am still having that problem.     I hate that.  I know I have to practice before doing my puppet shows and all.       

All I can say is practice makes perfect.   It does help if each voice you choose is very different.  So maybe one is high and the other is low pitched. One is a fast talker and the other speaks slowly. Giving one an accent can help also.  I wouldn't give them both and accent though, at least not when starting out.