I saw a thread that mentioned CoverMe and thought I would share an alternative setup for mobile.
Enable full encryption of storage. Android and newer iPhones have this option.
Enable pin screen lock (not facial rec) and habituate yourself to entering extra numbers and deleting them as you move around entering your pin in public to help cut down on shoulder surfing. Turn wi-fi and bluetooth off when not using them. Some apps will manage this for you but can also suck if you are trying to update music and the app kills your wi-fi in the middle. I do it manually.
Use a reputable security and anti-virus program but understand that even great anti-virus software is a day behind many threats. Limit your exposure to risky activities including the obvious pr0n, social media, apps from the app store that you cannot verify otherwise, etc.
Now the cool stuff: WickR for messaging and then Tutanota for e-Mail. I believe Proton mail is still full although it is similar to tutanota and sounds less ridiculous when sharing with friends.
Whatever you use do it consistently and pay special attention to companies that volunteer to give private keystores to big brother. More than a few "secure" e-mail services have given copies of all keys over to one agency in particular after simply being asked to comply.
Secretum est libertatem