If you are well-qualified (Tier 2 or Tier 3 preparation, high GPA, high quantitative GRE score, research experience, good letters of recommendation), you should apply to all of the top-ranked economics departments and several backup schools. You should definitely speak to economics faculty members about this.
If you have a somewhat weaker record, don't apply to the top-ranked economics departments. Do your homework and talk to economics faculty members where to apply. Many of the middle-ranked programs have generous funding and excellent placement records.
You should not initiate contact with faculty members at schools where you are applying before the admissions decisions. If you are admitted, you will have the opportunity to communicate with faculty members and make a visit.
Top-Ranked Economics Departments
Middle-Ranked Economics Programs