https://coinsutra.com/make-bitcoin-paper-wallet-spend-bitcoins/

It takes a little work, but it's the most secure way to hold bitcoins.

Some ATMs generate paper wallets for you but then you have to trust the ATM operators. They're also usually printed on thermal paper so it's wise to transfer them to paper wallets you generate yourself.

It's also a good idea to print them on a printer that is never connected to an internet-connected computer. Printers can be hacked.

Spending is easy. Just use the sweep option of a mobile wallet. In Mycelium  wallet, tap the 3 little dots in the upper right corner and choose "Cold Storage".

This will allow you to transfer all the coins to your wallet app. If you don't want to spend all your coins immediately, you can transfer the remainder to another paper wallet.

This is why I prefer to keep my coins in many wallets. You can sweep a wallet with only as many coins as you want to spend or feel comfortable carrying in your phone.