How about learn it by heart and make sure not to get too wasted and completely forget it? Indeed not that trivial, there is risk involved with whatever option you go for.
Jokes aside, would one option be to divide up the seed and give it to three people? One maybe even a lawyer or so? Or even 6 people, so 2 times 3. That way you have a copy of it.
Actually I think this is a great idea and lot much safer imo, i don't think it is a joke, if anyone can use a combination of things names they are familiar with on the phrase there is very little chance you will forget this combination, because as much as we try to be care and protect our hardware wallet, there is still that chance of misplacing it some how, but if anyone is able to memorise keys as well as write it down somewhere safe in lock and key that will be even better.
No, I mean on paper. Say you have a 24 word seed phrase and you split it up in 3 x 8 words and distribute two copies of each to 6 people you trust. It is important that these six people don't really know each other. At least those who hold a different piece of paper shouldn't know each other. You could give two copies of the same to family. But there is another risk: imagine you start an argument with your family for a weird reason and two siblings unite against you and don't want to hand out the third piece of the puzzle and blackmail. This is a complicated problem.
What about a system that works with smart contracts and oracles. For example, you store your seed in a digital blockchain-based vault. The login to that vault is a specified email. It only opens if you type in the password, and a specified so called 3 out of 4 multisig. For example, you could specify that if in a certain time window I log into the vault, say between 3:00 PM - 4:00 PM timezone x, in that time window I use my 2fa on my mobile phone (authenticator), log into Facebook, Linkedin or Twitter (3 out of 4 in total), then my vault opens and I can access the seed. If it does not work out because I lose my phone and I don't know, Facebook is down, I can specify a second email address that a code is released to after say four weeks of not logging in. If the vault afterwards still is not accessed, the vault assumes that I am dead.In that case I can specify the procedure that ensures my heirs get access. For example, specify their email addresses to be contacted next with the necessary instructions to access the vault.
Does that make sense?