I do mine in a microwave. I've tries a couple of brands and one in particular is superior, but it is local to UK.
I usually mix in some crushed nuts, dried fruit, cinnamon, honey. In summer I add some raspberries from my garden.
I cant drink cow milk any more so I make mine with almond, rice or soya milk.
I get stuck in a breakfast rut very easily, so I try to change the additional bits, eg different types of nut.