Negative keywords are words you add to stop your ads from showing on searches that are not relevant to your business. Before launching, it is smart to think about what kinds of searches could trigger your ad that you do not want to pay for. For example, if you sell paid software, you might add words like "free" or "crack" as negatives. You can also look at Google's keyword planner to spot risky terms early. So what do you think is the best way to build a negative keyword list before a campaign goes live?