Every time I go to a new planet I save into a new game save. Yes, I end up with a lot of game saves that way, but at worst, I'll only have to go back one planet if the savefile gets corrupted. On games where you can't do this(e.g. Resistance), copy the save to another user or to external storage occasionally.
I just lost a gamesave myself. Good thing I had another save because I'm trying to do the Everybody Dance Now skill point and that's all I have left. If I would have lost my original I would have had to start everything over from scratch.