For non-significant amounts that you want to be able to use in the go, you can choose to additionally have a hot wallet (others have already mentioned MetaMask for ETH-based, for example).
If you do not want to go the extra mile and want convenience, and have an iPhone, personally I think an iOS-based wallet is a more secure choice than having it on your desktop or Android device.
Save your BIP39 seed phrase offline (paper for example). Protect it with a pass phrase. If you want extra protection on the passphrase, there are solutions to “split” it using Shamir’s scheme to for example 2-out-of-3 and store the parts on different locations. (Definitely run this on an offline device, for example on a laptop booted from a live USB key)
Either way I advise against fully custodial wallets such as blockchain.com or crypto.com (commonsly recommended but not your keys not your coins).
With both, make sure to save the generated seed phrases, and use a strong password to lock the wallets.