i kinda know what you mean but thats the thing
i cant just write :
you are x
i like x
you help me with x
i like your x
and i cant just put it on a blank a4 paper
and kinda need to decorate it also
structure is also important
In seriousness, you can just tell the person some qualities you admire about them and you appreciate them in your life. It's just a nice gesture it doesn't have to be a big confession. If you wanna confess I recommend not doing that in writing. Oh, and they make valentines day cards so you don't really need to use white paper and decorate it unless you want to.