What do you add

A clove of garlic cooked with the potatoes and mashed in.
Boil parsnips with the spuds and mash in.

It's the variety of potato that counts. For a good flavoured potato, all you need is butter.

Olive oil instead of butter.
Grainy mustard in the mash.
A whole clove of garlic in the boiling water.
A sprinkle of garam masala or ras el hanout when shallow frying.
I love spuds

PP I was fine with the first 3 but haven't a clue what the last two are

Both spice mixes Spec, one Indian (l use nutmeg, cloves, cardamom, cinnamon, black pepper) and one Moroccan, a mix of toasted spices of infinite variety!!

I just can't see me trying those last two PP, but I thank you and everyone else for their tips, and will try the additions you have given me