1. A professional psychic with integrity will always do the preparatory work before the reading. I always do my daily meditation ritual, connecting to God and asking my angels and guides to protect and guide me throughout the day, including my session work. I cleanse my space daily. I also cut cords that attach to me during the day. Energy work is gratifying, however intense. After the reading, I always say a short or long prayer for the people involved. Do you think your psychic reader is preparing properly?
2. If a psychic asks too many questions before they start, be leery. Unfortunately, some charlatans who don’t have any psychic gifts want to make money. 
3. A huge red flag is if a psychic says you have a curse and you will need to be cleansed with multiple sessions that cost crazy amounts of money. They are scammers. Hang up or get up and leave. Do not pay them. I would report them.
4. A reputable psychic will always try to help. The reading is a no-judgment zone. Sometimes, people want to know everything will be alright.  They may have fears that are not valid, have negative cord attachments, and need to cleanse their space.

Finding a trustworthy psychic is like finding a good doctor or hairstylist. You have to have a good connection; no pun intended.