What is Your Security Measure for Personal Holdings?

I have gotten to the point where I need to take my security measures very seriously when it comes to my holdings. I have always been more of a cautious person when it comes to this matter. I have been hearing about this Chrome extension called Kerberus that has been helpful to some friends in the space but I wanted to hear other security measures the community takes to keep your personal holdings safe.

Do you have multiple cold wallets? Which ones are best to invest in? I know there was scrutiny about some of the cold wallet providers in the past and I was curious if the dust has settled around them.