When you file objections to your opponent's discovery, don't get carried away. Never object to every interrogatory or production request.
It's an obvious tip, but there are lawyers who do object to every interrogatory or production request. These objection-crazy lawyers are offering their opponents a gift: A chance to get in front of the judge and say, "Not only did he make frivolous objections to Interrogatories 1, 2 and 3, but he objected to every one of my discovery requests."
Sound unlikely? I've been able to say something along these lines quite a few times in my career, and it never turns out badly for me.
If you're going to make an objection, don't do it unless you have good reason to believe you are in the right. Otherwise, you're just offering your opponent a chance to paint you as an obstructionist--and you'll probably have to answer the discovery anyway.