DO: Establish traditions by which your group will be known.
DON'T: Shun regular practices.
Dynamic, surprising, and unpredictable a cappella group can be extremely entertaining. However, there are few things that distinguish a group over time more than tradition. Tradition gives groups a path to follow and establishes connections between all members, past and present.
Traditions come in many different flavors. They need not be large-scale, like traveling each year with the group during Spring Break (though some groups do make this a recurring practice). It can be as simple as having alumni come on stage to close your performance with a standard song, or putting on a regular show at a nearby venue. For example, University of Oregon Divisi, which was founded in 2001, performs every Friday at the EMU Amphitheatre in Eugene, Oregon.
The key is to give yourselves and your fans something to know you by, and to attribute to your group. Be consistent and build tradition.