The first button is a British Army "general service" button dating from 1890 to 1952. Need to see its back to have any hope of more-specific dating.
The second button appears to be a civilian "Fashion" button which mimics an actual military button. The details of the emblem are crude in comparison to actual British Military buttons. The odd "shield" at its center matches the one on the Royal Harwich Volunteers button, but the rest of your button is different from the RGV button.
The third button is also a civilian "Fashion" button, in this case a Sportscoat button, showing the emblem of the Royal Black Heath Golf Club, a famous one in Scotland. However, that doesn't mean it is actually from that club. Golf jackets here in the US have commonly had buttons with that emblem. Quite a few have been dug and posted by TreasureNet members asking for the button's identification.