I just watched June do a shed. At the end, she had retained shed on almost all of her toes (removed immediately by me, of course), which indicates to me that her humidity is not high enough. However, her humidity is the same as it's always been, and I'm following the same schedule of wetting down her humid hide. She's never had an issue with retained shed with me before. I'm wondering if leo's humidity requirements change as they get older?
if you keep track of the dates of sheds you can bump humitdity up a bit around the time they will shed, its happened a few times with goosebumps but if i jack up the humidity near the end of every month she gets though them just fine.
I actually put Hazel in a dish pan with about 3/4" of warm water every once in a while and it helps her shed easier. It helps with hydration and Hazel actually likes it. She is shedding every 10 days or so now for some reason. She swims like beardies do.
Another good way is to just provide a humid hide put a tupperware container with a hole cut into it and a wet paper towel in the bottom of it in the middle of the cage.
try stuff called frog moss, made by Zilla i believe. it is supposed to soak up A LOT of water and retian it better. put it in the humid hide and it should work really well im planning on trying it soon and will tell you how well it works.
also, as mentioned before, i usually mist the whole tank extra so the humidity is higher for them.