What are some signs that a therapist may have poor boundaries with their clients?

Obsessing about clients outside of work hours.

Frequent phoning or texting of clients to “check up on them and make sure they’re OK.”

Off the top of my ancient head:

How can I be okay with being ugly? What is the bright side?

These items can happen fleetingly, briefly, in any therapy, but if they’re frequent, it’s definitely time for the therapist to get some good, solid supervision/consultation.

General Introduction to Boundaries from Panahi Counseling:

Session-expressed curiosities about client details not relevant to the therapy.

Are you offended if Democrats call Republicans "weird"?

Disclosing feelings, fantasies, and experiences to the client in ways not related to the work the client is engaged in.

Eager anticipation (or anxious anticipation) of the next session in ways that distract.

Sense of competition with persons who are important in the client’s life.

Why do some people tell the girl I like that I don’t like her when I do like her?

Serious disappointment when the client cancels a session.

Failing to mention the client in supervision/consultation, out of fear the supervisor/consultant will advise return to ordinary healthy boundaries.

Struggling with fantasies of deeper connections with clients, whether sexual or parental or other intense or intimate relationships beyond psychotherapy.

What techniques can be used to sing like Freddie Mercury if one is unable to hit high notes?

Routinely going over the time limit with certain patients, compromising the time for the next client.