lastpass.com -use it, sync it with your devices - there is also web access!

Make sure you put everything in it! The chrome extension and mobile apps do a good job saving data automatically, but always make sure. Take the time out to create a manual entry if you have to.

Save everything that gives you access or identity verification for something - even if people tell you not to store the info online - a lost wallet seed is just as good to me as one that got hacked (Lastpass is very secure anyways)

I've been using it 4 years now, before Lastpass I used to recycle passwords etc.. a terrible habit to have!

Lastpass has saved my butt when I had to restore a wallet using it's seed after going 6 months without internet access, all my coins were there safe!!
Lastpass has paid for itself numerous times over the years, but did I mention all the great functionality is absolutely free?