My current strategy has been to write it on two different notebooks (one after another) and keep it in two different place.
This way, I'm not storing anything online or in screenshot. Unlike private key, seed phrase are easy to read and write in when needed.
By keeping two copies, I'm minimizing the risk of writing down incorrectly or having spelling/word mistakes.
By keeping them in different places I'm avoiding physical hazard and disaster like fire or destruction by other means.
The notebooks are kept in a safe place with at least a lock security, I don't specifically write what the phrase are for so that there's lower chance of getting my coin lost as a theft or robbery.