This all boils down to budget, because if you can afford why not treat yourself? By this time I'm sure you know who is coming to your event and how much you plan to spend. With this knowledge in hand you want to dress (the venue) to impress with out hitting skid row.
The first neat trick is to focus on your stage area. Just like going to a fancy show the first place a person looks at is depths, so hit them with all you got on your stage.
Second thing a person does is scout out were they plan to sit. This is were elaborate and well imagined center pieces dazzles the eyes. Center pieces gives you a lot of wiggle room with cost, because they are a combination of many items.
By focusing on those two items first you will befuddle your pickiest aunty and competitive siblings. Shhhhh lets this be our little secret.