Well, whilst the American 'traditions' (from recent times, really) of Trick or Treat are making inroads here in the UK, we Scots like to keep to our own, ancient traditions of 'Guising'. We (and the Irish!) like to think that our traditions were taken to the US and transmogrified into your T&T. 'Guising'.. This is from the word 'disguise' which tells the story. Children disguised themselves at Halloween! They visit neighbours and are usually given something like an apple or nuts or raisins... but ONLY if they do a 'turn', eg sing a song, recite a poem, do a dance... There was no 'trick' element to the ceremonies.
Halloween parties have traditional games, like 'dooking for aipples' (aka apple bobbing in other parts of the world!) - a large zinc bath is filled with water with apples floating in it - children are expected to try to bite the apples (with their hands held behind their backs)... Strings from the ceiling with a treacle smeared bun or apple... again to be caught in the teeth, with arms behind...
Nuts: 2 put into the fire in their shells... if they 'spark' together, that means a happy future life with your spouse.
Combing your hair and looking into a mirror reflecting a mirror behind you... if you do it - you MIGHT see your future bride/bridegroom.