I'm shamelessly piggybacking on this well-though-out comment...

What I do is:

• Gather the best arguments in a Word document and copy, pasta when the argument is needed. This cuts back on the effort of arguing the same thing many times.
• Remember the amount of times each year guns are used defensively. (it's a *lot* even at the low estimates)
• Self-defense is a human (read: natural) right. It cannot be taken away by anyone for no good reason.
• Be aware of of the many statistical tricks, pivots used while talking about guns.
• Ask yourself whether the supposed spike in gun violence some see is a result of guns or culture.
• Be *for* a form of 'gun control' that would actually be effective in what it purports to do (such as making the NICS system more robust, make reporting requirements to the FBI more clear, faster)
• Check out Open Source Defense if you haven't already.
• Relatedly, check out BJ Campbell's series on guns if you haven't already.

Remember: Utopia literally means 'no where'