1. download the app.
2. create the wallet.
3. save your wallet address.
4. save private key/seed. (on your dairy or print it.)
5. possible to convert QR on key/seed. (then print)
6. When you run out of needs. Then uninstall the wallet app.
*In this case, even if your device is damaged/phishing/malicious attacks, your money will remain intact.
These are my personal opinions, I have read some such blogs and watched some videos, which now I can't remember properly.
And if an unexpected disaster occurs, like a flood or a tree falling on your diary and, coincidentally, damaging the paper you used to print the private key or seed phrase... and you end up losing it all. Going back to the commonly heard phrase, "nothing is 100% secure."
It's better to prepare a backup for storing the private key... there are many ways to do it. You can store it online after encrypting it first. Or you can also write it on a disaster resistant object, so it can last even longer in your secret box that you can pass on in the future. There are still many ways to secure our seed and key.