I know this is a phase, but do you have any tips for helping your toddler through it?

DD1 will have days or times where she is the best, most caring toddler in the world. Other times (which is becoming more and more frequent), everything and anything is hers. It can be the obvious things, like her drink or toys, to the less obvious; other kids' toys, my hairbrush, a piece of playground equipment she has just played with/played with last week/thought about playing with a year ago....

Like I said, I know it's a stage and typical behaviour, but I'm finding it embarrassing (so I guess I'm the one with the problem). Any ways for helping her through the stage as quickly as possible?