I don't know, this might be the worst advice ever but sometimes I put just a tiny drip of water (very little or else it won't work) in the mascara when it gets too thick real quickly
Maybe some people consider that it helps bacteria grow, but I don't use mascaras for years, so I usually do that, if it becomes too dry.) Also tried it with YSL, but the result was not better than before it.. Though I like the smell of this mascara, not chemical.
I almost always comb eyelashes before mascara dries, because it really make it better. Although I prefer using old mascara brush, for me it works better than combs. There are brushes for lashes, which look like this , I find them more helpful.

