Programmers learn their programs and forget Naive users do not
Working month on a software undate blinds the helf maker to how a Naive individual *me" understands as well. Make sure that these new items can be handled by the Naive customer. Some idea whoulc be: Flag new features, peraps a flag until the user has awareness of a change in how to use the new feature. Provide a trail to get to the steps needed. Validate the user interfae as usable - the Naive User undertands less then the programmer. Provide a "fiinder" - for example I once forgot safe mode. I got into it fast and then spent lots of time to reverse the product.
I do suggest sstrongly the idea of a new feature flag, Some of the changes in Word for example change how things are done and i spend a lot of time trying to find where something as gone.