We used to assign a chapel to each student’s father. This has the potential to encourage good parental involvement, but in our case I think it got stale after a while. Lately our administrator has been doing most chapels himself and using them to highlight issues (such as respect, for example) that he sees as areas of needed growth among our students. I’ve seen positive effects.
We sometimes have people from missions and other ministries come for chapel, and these tend to be especially worthwhile times. Recent guests have included representatives from the Gideons and a pastor from Ghana.