Decorating a small plain space...

I don't have any good ideas aside from ceiling draping. I suggest spending some time on Pinterest. Also, I think it being a smaller space will make things easier for you.

@tania ... I have to say I'm super happy you commented with that question... You made me think about the ceiling in the room and realized that it's an angled ceiling and that balloon idea won't work at all! You just saved me from buying a bunch of balloons I wouldn't even be able to use!!

Lighting is probably the most important part in my opinion

Pinterest and youtube are the best for inspiration

Uplighting, draping, centerpieces, fancy linens. If it's in your budget, hire a wedding designer.

Up lighting?

If you focus on the tables and the decor people do not pay attention to the walls. If you are having a sweetheart table, bring in a backdrop and let that and your cake table be the WOW FACTOR for the room. Tons of things you can do. But don't think about the ceiling. Even if you have great linen with average flowers this goes a long way. Good Luck

Do you happen to have a picture of the actual ceiling? One of the best tips I learned early on in my event design career was to look up when I walk in a room. If there is a drop ceiling you can hang lanterns or air-filled balloons from small magnets. How about pennant strings, or twinkle lights like Mrs CK suggested?

As pp mentioned, if you bring the focus to the table top and maybe use simple uplights around the walls, the ceiling will disappear.

This is the room! (There's more space behind the person taking the picture but this shows the ceiling pretty well. I do love the twinkling light idea!! Thanks so much ladies your advice has been amazing so far