Only use it for what you're willing to lose
I use LastPass, its extremely convenient, but doesn't mean I have to use it for everything. I layer my email addresses and passwords - junk combo for throw away sites, medium combo for websites which have no exposure, both in Lastpass. And thirdly my main email address and a strong password based on a sentence which I memorise for banking and sensitive stuff which will never see any sort of password vault ever. If someone hacked my lastpass it would be inconvenient, but they'd get nothing..