"He and his wife came in here and were dressed poorly, fought during the meal, berated the staff, and were lousy tippers." 

Try to determine what the price ranges for houses are in that area and dress the part.  

Carport would double up as entertainment/grilling space and you could run a partial arbor across the front of the house to dress it up.  

Just dress well and talk like a professional.  

Or should I walk in the door dressed to impress?

Tenant Happy.Landlord sleepy.2 am Fire Dept. calls.Fire at such and such a place.We get dress.

Always present the deals with good window dressings.

Below you can see the agenda I copy and pasted:6:30 – 7:00 pm: Networking and Deal Making with your fellow investors (both new and active)7:00 – 8:00 pm: Main discussion: Houston Real Estate Market Report8:00 – 9:00 pm: More networking and Deal Making____________________________________________When: Thursday, February 25Time: 6:30pm - 9:00pmWhere: Pub Fiction (We will be in the room on the left)Dress: The dress is always casualInvestment: There will be no charge for this meeting.

Also I've found if I dress professional and walk around taking pics with an iPad (phone doesn't work) of a vacant house neighbors generally think I'm with the bank or the companies the banks hire to secure the property and winterize.

To me speculating is gambling dressed up in a nice suit.