How do you get yours kids to share?

I have 2 girls, one is 3 1/2 and the other just turned 2. The youngest wont let the eldest have anything. Everytime she picks a toy up the youngest takes it off her and it's getting silly. If you ask the youngest for anything she'll give you it, just not her sister. I've tried all I can think of but was wondering if anyone else had come across it and what had worked for you. Looking for advice only please.

Hi Sym, gosh that sounds hard work i feel for you.  I've just got holly my 2 yr old a star chart as she is being awkward at meal times but it also helps with sharing and being a good girl, as we go through the day if she is good we tell her so and that she will get her sticker at the end of the day but if she acts up we tell her that she might not get her sticker so she has to be good - so far its working and we had no issues tonight with her eating up all her tea, and she was super giddy at getting her star.  Its certainly worth a try for sharing, lots of luck