I’ve been doing thst fourth corner trick since I was a kid (a very long time ago). I’m short and it’s the only way to get tights bottom sheets on. The problem with sheets now is that they are too big - meaning most are made for the really deep-sided mattresses - which we do not have. I’m still grumpy about manufacturers inly selling sheets in packages with both too and bottom - and nit selling bottom sheets by themselves. I have a very worn out bottom sheet but the top sheet is just fine. There. Just be bottoms sold,somewhere.
Sandy in Mooresville, NC