You will see this said many times, but it is important:
Although your seed phrase is similar to a password, it cannot be changed. If it is lost, you will not be able to access or transfer your funds. If your account is compromised your only mitigation will be to create a new phrase and migrate your wallet. Depending on your hodlings this could be a substantial undertaking, and it will be a frantic race against whomever has your seed phrase; you can assume an attacker will move quickly. For something like a POAP it's not a big deal, but think of this as a low cost/low risk opportunity establish good habits!
While it is tempting to think "No big deal, I'll just write it on a piece of paper and put it somewhere safe" you must remember that the price for convenience is risk, and the consequences are absolute. Maybe a piece of paper would be good enough if you have a small amount of crypto that you wouldn't feel bad about loosing, but even then there are horror stories of people crawling through landfills searching for bitcoins that they thought were worthless. In the early days people didn't think the digital currency would be worth much. One example is in 2010 when someone spent 10,000 bitcoins on a pizza (at today's valuation, that is hundreds of millions of dollars). If you are storing any significant amount of crypto then loosing that seed phrase would be catastrophic.
You will want at least one redundant copy of your seed phrase which is stored in a separate location. An even better approach would be something like Shamir's Secret (AKA "2-of-3") which requires splitting out the phrase into 3 specifically crafted partial copies, where any 2 versions are necessary to identify the complete phrase. Bonus fact: Shamir is the “S” in “RSA.”
Since paper can easily be lost in a fire or flood, stainless steel has become a popular option. There are a variety of products available for purchase, and if you are ambitious you can even DIY your own inexpensive solution.
If the idea of being wholly responsible for your digital assets sounds daunting, you may want to consider utilizing a trusted party that has a track record of safely storing physical valuables. While utilizing something like a safe deposit box may not fully embrace the ethos of "my keys, my coins," you may find that to be a reasonable compromise. For those with substantial holdings, you may want to consider entrusting a dedicated crypto custodian.
At some point you will encounter someone who will proudly display their fancy super secure wallet and brag about how much they've made. Don't be like them.
A lot of great alternative solutions are likely to emerge in the next coming years, but there are a few options which I would generally recommend against: