You can do various things. Only the words' prefix matters (3 letter prefix for English, 4 letter prefix for all other languages I think), so you can modify the words (ie, if your seed has "marble", you might choose to replace it with "marked", for example). Now, you have what's essentially a stream of bits, and any general way of "hiding" these apply.

You could encrypt it (eg, GPG with your own key).

You could apply some "well known" transformation, such as writing it down backwards, etc.

You could apply steganography to store it into a picture of a cat.

You could do all these things at once.

But the thing to remember is that the more you process your seed, the more likely it is that you will misremember one of the steps. Could be you'll lose your GPG key, forget your password, delete the cat picture, forget it was the 4th word you swapped with the 8th, etc. So if you do any of this, the exact steps to "unhide" the seed are as important as the seed itself.