loulou welcome to the site i've been making small batches of royal icing
generally it is made with 16 oz pkgs of confection sugar some refer to it as icing sugar i weigh out 8oz confec sugar add 1 T and 1/2 T i do not pour in all at once i use warm water and add T by T usually 2 Ts then I just drip in droplets until it gets to hard consistency where you lift the beater and doesn't drop off i do not beat on high speed maybe set on 3 or 4 (kitchenaid I'd have to look see what it is on Cuisnart) for other consistencies i put some aside and add water little by little stirring each time by hand hope this helps this doesn't make a lot but the amount you do get suffices just for practicing and actually for decorating you don't want to have too much icing where you don't use it i try not to have a lot so that i don't always have to re-work it hopefully american measurements suffices sometimes i'll also weigh by grams to me grams are more accurate shrugs