Good attorneys are knowledgeable about your case's area of law or laws, will reply to your inquiries, let you know quickly if they can take your case or not, keep you in the loop about how your case is progressing, and explain in detail the issues you are facing. A good attorney is able to master both customer service and legal skills. Good attorneys are also not necessarily found through prominent advertising or marketing; many good attorneys are very experienced and do not advertise, because they do not need to spend money on billboards or other advertising to get all the work they can handle.
Good attorneys know when to turn cases away or to refer a case to another attorney. Maybe a case involves an area of law which an attorney does not practice in; the proper thing for an attorney to do in this case is to refer the prospective client to a knowledgeable colleague. Or maybe the case simply involves an issue which probably cannot be resolved through the law (e.g. forcing someone to apologize).
What are some signs of bad attorneys?
1. Promising results; nobody can predict the future exactly, and cases have so many moving parts that it is impossible for any lawyer, no matter how skilled they are, to be able to promise a certain result.
2. Taking your money and not replying to your inquiries; this is a common sense customer service metric.
3. Spending a long time on your case without progress; often, litigation can take a long time, but a good attorney will be able to explain what has been done so far, why there is a wait, and what needs to be done in the future.
4. Missing deadlines; attorneys who miss deadlines jeopardize not only their livelihood, but also the rights of their clients. Some courts and judges have rules where missed deadlines can result in an automatic finding against a party, even if it is purely the attorney's fault.
*I am not, however, factoring in the non-monetary value of personal vindication, reputation preservation, etc.; for example, if the plaintiff was a celebrity, it may be worthwhile to pursue such a case.