ok first, it's not up to flat earthers to prove themselves. We feel no movement, see no curvature, and there is nothing in sacred scripture about the earth being made round. It's up to globe earthers to prove themselves.
What we flat earthers do is condemn globe earth as both a scientific and theological error.
My PERSONAL favourite way of doing this is the fact of seeing objects over the horizaon.
Any of the "convincing" videos in this thread
http://flatearthtrads.forumga.net/t17-objects-over-the-horizon-proofs (except the one on mt taranaki) is good.
This one is my favourite
You see globe earthers have now back themselves into a corner declaring a fixed rate of curvature based on a fixed circuмference. With high zoom cameras it is easy to debunk this with images which are clearly not refraction because they are too steady and integral.
And goodness, while I'm happy to hear that Ireland is clear on this, it is by no means the only place.
You can't make this go away because it is the truth.