i have some left over tiles from new shower and wonderd whats the best thing / things to make, and how to make it?

are they porcelain tiles? If so sand your rough edges, i just slid the edges on the concrete a few times and they beause perfectly flat. I use mine like crates, some non sliders under them and they are pretty fun.

they are quite big like strched hand size

Put them on top of a colgate toothpaste box and you're good to go

Use a angle grinder and make sure its a tile blade and you can cut them