Knowing we play the game differently my input might be less interesting, but... I play rotationally with aging off. Every New Years Eve I turn aging on for just one night. Assuming sims still age up at midnight, only. Then I age up all households including non played , so they all sage with the same pace.
In addition to this, and this is what might help you too, I keepo track on every played sim wirth details, in a spreadsheet. One line per sim. This includes their age, making it easy for me to see when each sim is due to age up. I play on average (I think), 13yo = teen, 25yo = YA, 50ya = A, and 70ya = E. Only in very few cases a sim have already aged up when I stop by to age him, up.
Re the transmition from A to E. I think the change from Child to Teen is a bigger problem. Sometimes I make the A look a bit older wjhen there's only a handful years until Elderhood. This is easy to add by face details, adding glasses if needed, adjusting their clothing and makeup, and not the keast: I love the hair color where black and brown has a hint of grey. I so wish we had this option for red and blond hair as well. For some Elders I might make them a tad younger for the first handful of elder years. The same hair color (brown or black with hint of grey) is again perfect). It helps knowing how much a certain sim will care about these things. And if say an elderly woman will go for makeup or just skip most of it. I know these things from my residents registry, so I can adjust it according tho the sim's wishes, securing some variety.
Thank you! I tried the hair colour thing even before reading this post, and while it doesn't work for my Sim mom because she's blond, it should work for her brown-haired husband. I was thinking about adding glasses, too. I like the idea of turning on aging on a specific date, I'll keep that in mind :)
