Make decisions without first vetting and verifying by consulting with a tax, legal, or other professional.  

Do not make a major purchase before you close on the property.

Go knock on the door of the seller and start asking questions without my knowledge or assistance.

Move money.  The majority of headaches in the lending world come from people moving money around when they're prepping for a real estate transaction - they get frustrated, we get frustrated because they're frustrated (as a result of their own actions) and it makes what should be an otherwise easy process more difficult than it need be.

Yours is a good one. Mine? Do not, I repeat: DO NOT talk to anyone & instead, refer them to me. That is your part. I will do mine! LOL as clients always talk

Seller - block showings

Buyer - not buying a new car after approval and before closing. Just any run of a a credit card balance.

Get a new credit card or car during the buying process.

we get into a discussion of clients vs customers vs leads.  it all gives me a headache.  loyalty is a top word on my list.  

I hope they won't make major purchases between the time of contract, and the closing date.  I can't tell you how many times a client has pulled up to the inspection, or at the walk-thru in a brand new car, even after I have told them, ad nauseum, not to make any major purchases until after closing.

Had a potential client sell with action company. Instead of the seller paying us 5% the auction company charged the buyer a 10% premium. She was so proud that she didn't have to pay any commission. Worst...deal....ever. 

We try to caution them to follow our advice and ignore the busybodies in their circle of acquaintances.

Do you mean during the transaction, or after if they don't know what they're doing and the implications?

I worked with a lot of young people stationed on the AF base and some of those young people didn't pay attention when I told them NOT to buy a new vehicle before closing KAREN SANCHEZ 

Work me over commissions. Had a couple of bad experiences.

If its a buyer who is my client I don't want them side-stepping me by going directly to the seller..no good ever comes from it.

Badmouth me.