I created an Excel spreadsheet that breaks out the data of a barcode (you read it with a barcode reader app, then paste the text into the spreadsheet). It's all openly documents on what information is in what position - name, cities, flight, ticket numbers, number of checked bags, airline, frequent flier number. Some of the stuff in the airline dependent area can vary but overall it's well documented and contains a lot of information for redundancy.

Personally I shred them once travel has finished and miles/segments have posted. It used to be a bigger problem when US was *A and I credited United flights to US - it wasn't 100% reliable that miles would credit between the two airlines.