How to best manage the joint between different wall tiles?

[shediyer]

Hello all, I'm tiling my bathroom and using 360 x 240mm white tiles on the main walls, and 100 x 300 green subway (not metro) in the shower area. Can someone please tell me, what's the best way to manage the join where these two meet? Should I just butt them together with a 2mm grout joint, (the two types are the same thickness), or is there a tile trim i should use? TIA

 

[J K Tiling Cornwall]

Maybe just keep a 2mm grout joint was going to suggest a chrome insert but might look like the shower area was originally tiled then the rest of the bathroom at a later date as different tiles. Some pics might help 👍🏻