I can only tell you what has worked in my school. I work in Abu Dhabi and we do two different kinds of parent involvement activities. The first is an open day at the end of each theme unit. The themes last one month and at the end of the month, the parents are invited in to participate in activities that relate to the theme and also to look at the work the kids have produced that we have hanging up. This does add to the workload of the teachers so please volunteer to help in anyway possible. The other tactic we've tried is having moms come in to do grunt work for the teachers. We, the teachers, give things that need to be cut, folded, stapled, etc to a point person at the school and moms come in to work on it once a week. Some moms only want to work on things for their child's classroom, others don't care what they work on, but it does get them into the school and the teachers really appreciate having someone willing to fold and staple together 23 letter books!

A friend of mine also used to organize her school's field day and they used parent volunteers to run the games. She said that parents would ask at the beginning of the year what day it was scheduled for so they could make sure to have the day off. But someone else will have to give you guidance on that.