This practice, that has been used for generations, was adopted many times in our household. It helped prevent many arguments between our two children. Basically, to ensure food and/or drinks are shared fairly and equally, one cuts and the other chooses. This process also works with more than two people, i.e. the one who does the cutting gets to take the last portion.
This has brought us a lot of entertainment over the years watching the kids taking on the responsibilty of sharing something as equally as possible.
For example, when our children were little, Coke was served as a treat. So, sharing equally was all the more important. Sharing a can of Coke between two glasses was very serious business and was carried out with extreme care. Imagine two little faces looking intensely at the level of Coke in both glasses as little drizzles were added to each glass, literally one drop at a time. It did not matter how hard one tried to share, the fact that the other one had to choose made them concerned they might still end up with the smaller portion.
It was such as important job that neither kids were sure if they really wanted the responsibility of pouring the Coke.
No money saving tip here, although this will save you time gaining a little sibling harmony!