- Do not use words or a set of numbers as passwords
- Do not use automatic password generators, it is better to come up with a complex password yourself, it may be easier to remember it.
- Do not use a universal password to enter all sites (exchanges, wallets, etc.)
- Do not store your passwords in the cloud and on Internet sites
- Do not store your passwords in a text document on your computer desktop
This is true about the best way to secure your password is by combining both alphabets and numbers not less than 16 characters, I've come across some sites which will show you an indication to how strong your password is, while some site will not even accept only numbers or alphabets only as password, they will insist you correct it by mixing both and atimes if possible with the use of symbols in addition.
Lastly is not how long it is but how fast you can easily remember your password, therefore its good to make use of the combination of what is close to you, precious to you or what you do often as part of your password combination techniques which are things you can easily remember.