NOT LEGAL ADVICE
My best advice is for you to talk to as many of your neighbors as possible. Some won’t want to discuss their lease terms, but most will. You can also try looking for images of their leases at the Dallas County Clerk’s Web site, and find the royalty amounts specified therein (you won’t find the bonus payments specified in the leases). See what they all decided upon and you’ll have an idea of what’s “fair” for your area. Keep in mind that prices of natural gas have dropped about 50% from their high two years ago, so don’t expect the huge bonuses that companies were offering back then.