How to respond to Gish gallops

• Full rebuttal. Go over every point made by your opponent, and refute each of them individually.
• Sample-based rebuttal. Select a representative sample of your opponent's arguments, either randomly or based on some criteria, then refute only those arguments.
• Thematic rebuttal. It consists of identifying the main theme of your opponent's arguments and arguing against that.
• Group-point rebuttal. Dividing the opposing arguments into distinct groups, then addressing each group separately.
• Best-point rebuttal. Addressing only the strongest piece of evidence presented by your opponent.
• Worst-point rebuttal. Addressing only the weakest pieces of evidence.

Different techniques will work better in different circumstances based on who your opponent is and what your goals are.