Hard for me to answer because I would have trouble myself.
I usually do what I like to do: invent fun stuff. That means no direct approach but rather use what has come out of convo to, for example, send her something, buy her something curious or cool or sweet. Like this girl whose last name was something like Sandlewood, that's a scent. I was planning on sending her (in her mailbox) a little flask of those things with some intriguing message to go with it, so that next time our meeting would be more special. I bailed in the end, I don't know, it could work out again some time. I always have these ideas but recently my life has been rather I would say misbegotten.
Another girl who worked at a hotel I wanted to send a DVD with some stuff I think one of these small ones, these 8cm ones. And some message, I knew exactly what to write. It also failed (I never sent it). I think it's just tough, I always like to use these less-direct but still-direct approaches. Something that intrigues. I always say: use your strengths.
If your strength is writing, poetry, or imaginative stuff, use that. It is even romantic. Although one girl I did send a letter to got rather emotional next time I saw her
. She kinda ran away. I don't know, maybe it meant too much to her. Like I said, I haven't been able to pursue anything.Being shy is not a problem. You just have to find ways to reach her, if a full out social real life face direct approach can't work as fast for you.
Supposing you had sent something to her that intrigued her and left her wanting more, next time you met her, you could say like "You know like, that message?" She'd go "Yeah?" You say "Want to do something more?" ... "I mean like, you know?" and she might just go Hmmhmm. Don't be afraid of your shyness. Be afraid of a lack of opportunities to use other forms of messaging.