I would second the guppies. If you have the same kind of platys I have they're almost too big for a 10g. If you're planning on keeping the babies, then absolutely, plant the heck out of your tank. Wisteria, java moss, christmas moss, etc. will do. Anything with a whole bunch of little leaves to hide in helps.
Oh, and if you can, get a breeder net to put the babies in once they are free swimming. They like to burrow and will get trapped in the gravel and die otherwise.