It depends, of course, on the quality of the water you start with. While travelling, you will often not have facilities for boiling. In a restaurant, ask for soft drinks, beer or fruit juice in a can or bottle, or bottled water. Water or juice poured from a pitcher is suspect, as is draft beer or fountain drinks. Decline ice cubes.
Tea is often safe, coffee somewhat less so.
Water purifiers can be very useful, especially for travel to more rural areas, where bottled water may not be available. Can be kind of hard to find in some countries. Wearing a wedding ring even if you're single is often recommended. Buying them in a foreign country can be embarrassing. Taking malaria tablets cannot guarantee that you will not get malaria in places where it is endemic.