I threw a fairly sucessful Jack and Jill for a friend a few years ago.
Here's my tips:
Limit your selection of drinks to a few signature drinks (i.e. 2 different beers , 2 coolers and 2 signature mixed drinks). Leftover, opened bottles of liquor or opened cases of beer can't be returned and are a big waste of money.
I choose to serve a meal and then put out snacks. I got lasagnas on sale at M&M's and served them with caesar salad & leafy salad with an oil and vinegar dressing, and rolls and butter. I then put out chips, cheesies, etc after dinner. This was by far cheaper than going the sandwich, salad, cheese, pickle, etc route because I could plan better and have fewer leftovers (i.e. I estimated the number of servings of lasagna and went from there). The meal was included in the price of the entry ticket (which was $10). I also had a cake brought out about 1 1/2 after dinner was finished.
I rented a legion to hold the party and saved money because I did my own clean up prior to the party and clean up after the party. I stuck to basic decorations - streamers, balloons, curling ribbon, plastic table cloths, fake flowers. The legion also had coloured lights and a disco ball so I made sure to turn both of those on.
I got a friend with a good stereo system to play the music and had everyone in the wedding party contribute CD's (I made sure to put a sticker on each one to specify who's was who's).
To raise money, I did a 50/50 draw, a liquor bottle draw, crown and anchor and a "butterfly board" (the bride had a thing for butterflies but you could use any symbol). I took several large bristol boards and printed off a couple hundred of the same butterfly but in different colours (I actually coloured them with markers - but then again, I'm crazy). On the back of each butterfly was a prize listing - I had bought some small cheap stuff from the dollar store (candy was actually a big hit), a few better items, and then a couple of really great prizes. As well, to fill them out, some of the butterflies listed free tickets in the 50/50 or liquor draws. Guests could purchase a butterfly for $3 each or 2 for $5. They would then go up to the board and choose the butterfly based on the front (not the prize listed on the back). Once it was lifted off the board, they found out what prize they had been awarded. This made quite a bit of money.
Basically, I approached it as a big party with a few money making ideas. The number one goal was for everyone to have fun; the number two goal was to ensure that the party didn't actually cost me an arm and a leg; goal number three was to provide the bride and groom with a little something (the bride had actually said to me she didn't care if they got money from it - she just wanted it in place of a bachelor party).
If you make it seem like a money making event disguised as a party, people won't have fun (and less fun = less money spent)
If you make it seem like a party disguised as a money making event, people will have more fun (more fun = more money).
The only area I've ever heard of doing these is Ontario 
