99% of the overall turnout of an event is based solely on location, here's a quick list of some things to take into consideration.
The style of the venue must portray the vision of the brand and the occasion of the event. Many things are to be taken into factor such as, "how professional should it be?", "Is the loaction appropriate?", etc
Make sure the venue has the necessary amenities for your event. Are the bathrooms large enough to accommodate the guests? Are the bathrooms clean? Is the registration area large enough to accommodate the guests? Is the load-in area appropriate for outside vendors?
Is the service staff at the venue professional, friendly, and well groomed? Do they dress appropriately? If hiring outside service staff the same criteria apply as well as whether they are familiar with the venue.
Is there a fee for the venue? If so, is it within your budget? If the majority of your budget is spent on the venue itself, you will compromise other aspects of your event such as food and entertainment.
Does the venue provide tables, chairs, linens, centerpieces, china, glassware, flatware? If not, does your caterer or must those items be rented from another vendor?
Is the size of the venue adequate? Most venues have a maximum capacity. Make sure you stay within those guidelines as experience has taught them that the comfort of the guests and the service is dependent on those numbers. By the same token, don’t book a large space for a small group of people. The event will lack energy and excitement and will be interpreted as if people “did not show” for the event.
Is the lighting adequate? Can you create the mood you desire with the lighting? If bringing in custom lighting, is the electrical wattage and outlets adequate?
This is so incredibly important as it is the first impression the guests will have. If parking is inadequate, consider offering valet parking.
Your event is special and should be executed flawlessly. Of course last minute issues can always arise, but if you are well informed and have carefully chosen your event venue you should have a very successful and enjoyable event!