A combination, if just lazing around at home, let DD tell me when wants to go, but I ask her if she wants to before going out or when out if we are at a convenient location - because as an adult that is what I do, I don't always wait till I 'need' to go, I go before going out or if am near a toilet and think might not be near one for a while, go before bed etc. Have also started asking her if needs to go before we sit down to eat - because fed up of getting up mid meal to take her to the loo - she has been TT'd 5 months or so now but did the same from the start.