Some things just aren't fit for purpose in their current state, and would benefit from being redesigned.
I've always thought this about the tiny tubes of super strong glue (didn't want to mention any names!), for example. I'm dyspraxic and quite often end up with stuck together fingers, due to how it gushes out 

And then the lid gets stuck to the tube, and you get about 2 uses out of it max. I did see one advertised on TV the other day, that comes with a brush, so this seems like a more sensible design.
There will no doubt be plenty of better examples than the above, but what products do you use that you feel would be/work better, if only tweaked a little?