Invite up to 8 teams to take part in a tournament to be run over 1-4 days. Typically if the games are full-quota teams then youd have two days of double-header ¼ finals, one day for the two semi-finals and then a day for the final.
You could also go for a one day tournament with reduced numbers on each team and reduced length games. Either way, make sure you get permission from your parent organization (if it is required), because otherwise the players may not be insured.
Youll need to put up a cup for the winners. Itll help attract teams if you can put up a set of jerseys or kitbags for the winning players. Get some sporting goods organization to sponsor these. Get the best quality teams you can as that will bring in the paying customers.
Start advertising the tournament about a month before hand and do some intensive adverting in the week leading up to the kick-off (or single day as the case may be). Get the local press to cover the tournament and perhaps a mention on local radio (if you can swing that). Remember to advertise in the areas where the tournament teams are located.
Charge a reasonable entry fee for the games. If you have a social club then make sure you open it (at least on the day of the final). Create a program for the tournament so that you can sell advertising in it. You should be able to get $50 per half page. This one should be considered for the nonprofit fundraising events list of any sports organization.