Whatever you prefer. I don't warm my soap or dilution water but other people swear by warming both. If you do warm the liquid(s), test the thickness of the mixture after the soap is at room temperature, not warm. Warmer soap will be less viscous (not as syrupy) than cooler soap.
Next time, it would be best to not bury your question in a totally unrelated thread, as you have done here. If you start a new thread with a well-written title, you'll get better advice from more people.