Once you have decided to rent a meeting room it can be set up to become an extension of you. Just like your regular office digs, most people will probably have a grasp of your personality once they enter it. Just be careful and abide by the guidelines that are imposed by the meeting room company you choose. Although the meeting room will likely be very liberal in what you may take into the space, some items may not be allowed in the meeting room.
Housekeeping should be a priority in any work environment. You never know who will step into your meeting room unexpectedly. You only want to give good first impressions and keeping it clean and clutter free is a requirement. Cleanliness and neatness demonstrate you have clear thoughts about your work and it makes you appealing to work with.
Tastefully decorate it. Hanging paintings and carefully placing figurines of favorite items or subject matter will show where your interests lie outside of work. Just be careful not to over personalize the space. I know two teachers who, like many others personalized their classroom. What made their classrooms unique was that each had two groupings of the items in the classroom. Most teachers had family portraits on their desks.
It was clear one of the teachers had a thing for Native Americans while the other hung movie posters.
The American Indian display was unique and very interesting in an educational type of way. The movie poster thing seemed out of place because it was about modern day vampires. Not so sure what the educational value was. The displays certainly were a matter of personal taste but if I was a visiting parent, I would question the educational value of the movie posters, miniature vampire figurines and other movie memorabilia. So just be careful.
The personnel at the meeting room office are used to honoring requests for special furnishings, specific office equipment and ornamentation. Choose high quality pieces to put into the room. Far better to have fewer pieces with greater value than to place a lot of shabby pieces in the room. This will show your good taste and will impress your visitors.