Your first consideration in making legal objections is whether you should object to a particular question. The objection dilemma is this: On the one hand, jurors don’t like a lot of legal objections, as they believe you are trying to prevent them from hearing all of the evidence even though you may have a legitimate legal basis for making an objection. On the other hand, you want to protect your record in the event you should want to appeal the case. In many jurisdictions, objections not made are deemed to be waived.
What is the likelihood of your objection being sustained and what is to be gained by it? Since jurors generally dislike legal objections, it may be self-defeating to make a lot of objections as to the form of the questions asked when opposing counsel can simply ask the question again in the correct manner. But as to critical substantive matters, it may be imperative for you to object to improper questions. Perhaps the best advice is to try to minimize your legal objections, and object only when you absolutely must.
State your objection together with the specific legal basis for the objection before the witness answers the question. For example, “Objection, your Honor. No proper foundation.” Don’t argue with opposing counsel as to the legal basis for your objection nor quarrel with the trial judge if your objection should be overruled. Make sure to get a ruling from the trial judge before allowing the witness to answer the question.
If a witness should answer a question before the trial judge makes a ruling and in fact the objection is sustained, move that the answer be stricken from the record and that the jury be instructed to disregard the answer (unfortunately, it is too late). But likewise, ask the trial judge that the witness be instructed not to answer a question until the Court has made a ruling on a legal objection.
Perhaps the best way to keep out specific objectionable evidence is to make a motion to the Court before the trial begins or at least before the particular witness testifies to exclude such evidence. This is known as a motion in limine and requires planning. You may also want to prepare a legal memorandum in support of your motion. This strategy has the advantages of being done outside the presence of the jury and having an advance ruling on the specific matter of anticipated concern before it even becomes a problem during the trial. Whenever possible obtain a protective order from the trial judge to exclude the objectionable evidence.
Finally, if your opponent should have an objection sustained which you are unable to cure and it is critical evidence favorable to your case, make an offer of proof as the trial judge may change the ruling upon hearing the evidence you proposed to present. You can make your offer of proof at the bench but make sure that it is made outside of the hearing of the jury.