Empathy is probably the most important quality you should look for in an immigration lawyer. Does he really care what happens to you? The sad reality is that some lawyers do, and some lawyers don’t. If you don’t consider yourself a good judge of people, bring along someone who is when you meet the lawyer for a consultation. Client reviews are also helpful in this regard.
Empathy is especially important when you are paying a flat fee for a defined service such as a visa application, because your lawyer will make the same amount of money regardless of whether you win or lose, and he can always blame immigration authorities if you are rejected. It is also particularly important if you are paying by the hour to avoid deportation — after all, your lawyer knows that if you are deported, he will probably never see you again anyway.