Creating an encrypted wallet of your own is a safe way to store your Cryptos without having to trust anyone. When you generate your own encrypted secret keys securely you can share the secret key without worry.

Use long, random pass phrases and generate from a secure and always offline machine. Use websites like https://ryepdx.github.io/ethaddress.org/#/ for ETH or http://bitaddress.org for BTC

Generating securely isn’t that easy though. A computer needs to be used that is either dedicated offline and airgapped, or a RAM-only Operating System needs to be used offline. This is to ensure that no ‘computer viruses’ can watch you and steal your keys. The ladder option can be obtained by using a plug-and-play operating system such as Tails.

In addition to using a secure system the pass phrase needs to be long and random. At least 10 words is recommended minimum, more is better. Never use anything from any published work no matter how obscure. Always use random words, use Diceware or dice and wordlist to obtain random words. This pass phrase, and the website or method used to encrypt the wallet are crucial to spending it, you cannot lose them. You can save a website for using in the future or even for online use. To do this rightclick and hit save. Practice before the game.