Storing your seed phrase is not an issue, but how safe you keep it matters because that is the only thing that can guarantee it to be well secured. Many people save their seed phrase in many ways that best suit them. As stated by some members here, you can adopt any of them that you feel is comfortable for you to go with, but the easiest is just to write down your keys and store them in any safe place where only you have access to, so that nobody gets them from there so easily. This is what I do, and I have my keys intact till today. Only I have access to my keys, and it is safe where I keep them.