We dooked for apples but we also had another game that involved apples in a washing up bowlful of water, you stood on a chair with the bowl on the floor and tried to spear an apple by dropping a fork on it. Also made turnip lanterns before pumpkins were widely available - carving a neep is MUCH harder though.
We did go guising ('trick or treating') too though only to houses of family and friends, and if you didn't sing you didn't get the goodies. It would only be wee short songs though, I remember one that we learnt at school when I was about 6 that went "Whose pigs are these? Whose pigs are these? They are John Potts, you can tell them by the spots, and I found them in the vicarage garden".
Hardly traditional or Scottish but it made me laugh hysterically when I was 6 :-)