Yes, I have, but I guess it is too late for you now. I have made carmel popcorn, and different flavoured ones using jello powder. I would have to look through my cookbooks to see if I still have those recipies, if you still want them.

Kay...I started to post this the night you posted your question, but I do not know that much about seasonings for popcorn or could offer that much by way of popcorn seasoning...but this is what I wrote.....

If you google 'popcorn party'...or 'popcorn seasoning recipes'...there are lots of ideas on line.  There are also seasonings which can be purchased already prepared, but that may not be in your budget depending on the size of your group or that you have the time to prepare.  Or use simple things right from the kitchen ...such as parmesan cheese or garlic salt or chili powder or lemon pepper or other seasonings...without doing a full mix recipe. A lil' salt and butter and a seasoning and it might be good. If you have time, do a taste test run at home with some seasonings on some popcorn.  

I do not know what you have to keep butter hot, but isn't there spray butter that could be put on hot popcorn?....or olive oil.......salt, etc. I have never given a popcorn party, but have served popcorn in my home in containers that look like and are shaped like a red and white popcorn sack or carton from the movie theater which is fun.  They were 2 for $1 at a dollar store. You can also find places on line for popcorn party containers and other items. I do not know the size of your group or any popcorn bowls you have available, but disposable bowls are an option, or small paper bags, cuffed. Due to the oil or butter, maybe double bagged, depending on the thickness of the bag.

Like I said, I have not had a popcorn party, maybe someone here has.  Let us know how it works out. Just plain air-popped popcorn with a lil' butter and salt is hard to beat.

                                          COATED POPCORN

8 cups popped corn
1/4 cup butter or margarine
3 TBLSP corn syrup- clear goes better colour
1/2 cup brown sugar
1 package (small) Jello powder...any flavour

Heat syrup and butter. Add jello+sugar and bring to a boil. Lower heat and cook 5 mins.

Pour over popcorn and toss until coated.

Bake at 300 for 10 mins...in a shallow pan.

Cool and break into pieces.

*If using grape flavour, use 2 pkgs or a large one.

*Sparkling wine/grape Jello is excellant