Minecraft – Riding in a Minecart

Above ground, you can use the sun or moon to orient yourself. They both rise in the east and set in the west. Also, according to an answer here, you can punch the ground, and the pattern of cracks will always be oriented the same way relative to north.

Finally, there are third-party mapper programs that you can use to orient yourself (although I haven't used any and can't vouch for them). Some players might consider this cheating, or at least unsporting.

Instead of a button you can use a trapped chest that the player needs to open; for this is much easier to hit. Another upside is that the chest closes automatically when the player gets out of range.