What techniques do professionals use when working with someone who suffers from a borderline personality disorder?

There are many: One of the more popular therapies is dialectical behavior therapy where patients are urged to use their "wise mind" to slow down and not make snap judgments about people or situations. These therapies teach patients through self reflection to see the world in less hostile terms. More functional behavior patterns can be learned.

Counseling : Counseling (dbt) and medications are used to help individuals with borderline personality disorder.

Borderline: Most effective therapeutic technique is dialectical behavior therapy.

Multiple therapies: People w/borderline pd benefit most from combined approaches. First, individual psychotherapy with someone skilled in object relations work, along with dialectical behavioral skills groups. The latter helps deal with intense affect, gaining skills and tools. Object relations-based psychotherapy provides insight into interpersonal difficulties, allowing change. Medications at times too.