If you are switching jobs:
The replacement of job should not be a justification for labelling the workplace you have worked in as poor. You should say to your boss why you are leaving the company and you ought to point out the things that bothered you, do it in a polite and professional way however. Keep a measure of professionalism that has led one to this point in your career. This assists one to make strong references in the future. In conversations with brand-new potential employers, it is necessary to be professional.
You should also tell your superior that you are grateful for the opportunity that you have had in working for his or even hers corporation. You won't ever know when your current boss will prove to be a great reference. Be aware that no one likes to become criticized. Not from subordinates or colleagues. Even if they should have it. A person with whom you possess ever worked with can be a possibly positive reference. Usually do not demolish the bridges behind you. Keep genuine contacts.