Keeping Bitcoins in clients like Electrum, that you can restore with a 12 phrase key, are one way to keep the coins to relatives since you store it somewhere at home and your relatives will either find it or you tell them about it and they can worry about it once the day are there. All they need is to download the software and punch in the words.
Other clients, that doesn't have this mechanism, are more troublesome. Like with Steemit you have to keep your admin access token available for them to read once the day are there.
You can store these items on password protectors like LastPass or a web drive with encryption, but you somewhere have to be able to write down a set of ways to access these and how to decrypt them. It can be troublesome since you don't want to have that laying around unsafe.
Optimally would be to have family and/or relatives that are interested and know what to do once the day is there. They don't have access, but they know how to get it.
I think it's as important to talk to your family and relatives about this as what you think about organ donations after you die.
That's a very good idea @sc-steemit. Thanks for you contribution. The issue here is that most of them are not interested in having anything to do with cryptos.