What should I do next?

So I met this amazing girl a few weeks back and we started to get to know each other and it was a lot of fun for us. This girl, I feel, is pretty much exactly the same as me, we both like exactly the same things to the same extent and both hate things to the same extent as well.
We met up just the two of us yesterday, but it didn't feel like it was just as friends or that we were going out or anything. From what I felt, there was some sexual tension between us the whole time. To be fair I did miss my opportunity throughout the day as she was dropping hints throughout, as was I, but nothing happened, even at the end nothing happened. I know I should have done something but I know I missed my opportunity.
I am just not too good at making the first move, even if it is obvious that the girl is into me, and is obvious to everyone.
This girl is just amazing and I do not want to lose her.
The only problem is that she is going back home (I live in Australia, and she is in Slovakia) so it is just to far to do some big romantic gesture. I have tried long distance with other relationships and the only reason they didn't work was because of the other person not being committed. I feel like it could work between us even though it is long distance. I do go over to Europe almost every year for a month or two on holidays so we can see each other then, and I plan on going on exchange in the next year or two then moving over there in the future to live and work.
We still talk/"low key" flirt but nothing is yet official. She leaves tonight to go back home.
Please give me some good advice I am serious about this girl.