I always use the UK version to cook the potatoes and then do variations according to what I am serving eg.
Add good quality olive oil instead of butter or milk and then possibly add spring onions.
Add horseradish paste and milk - good with, eg. mackerel or beef
Add roasted garlic
I have thought about putting a clove of garlic in with the potatoes as they are cooking but haven't got round to trying it yet - like a lot of my ideas, they take ages to come to fruition
I find that it takes a different amount of time to mash each time I do it, so I do as JD does and only run it for a few secs. before checking and adding more liquid if necessary. Not a very scientific approach but it seems to work for me.