A lot of ladies have given really good advice so far. I know I would not like to be rushed at the last minute in getting my hair done without forewarning but if you are REALLY limited for time (like 2 hrs), I know I would probably get my water filled spray bottle, some gel and/or strong pomade, scarf, and a brush and slick my hair back into a bun. Then tie up w/a scarf to set it. Put on some nice dangling earrings and go.
Or .. since you had twists you could do a twist out up do-just work with it. Just use some bobby pins and twist/pin up the back section and pin up/bump up the front (if that makes since). Add a nice head band and go. The twist out doesn't have to be perfect because its in an updo form.
Hair accessories always help.
For sets like twist outs, braid outs etc, they take time to "set" . I do agree with the tips everyone has said about braid outs/twist outs:
**Always make the last rinse you do a cold-COLD water one. It helps.
**When you do a set, make sure it dries completely before you touch it.
**Get a good leave in conditioner on damp hair and seal with ur ends with an oil or light butter when the hair is almost (not yet) dry.
Good luck-don't give up just yet.