[header] How to know when not to volunteer [title] Stop offering to volunteer if you do not have the time. [step] If you cannot devote the necessary time, be aware you only have so much time to devote to anything. Volunteering is no different. 
You can create problems for other volunteers by not turning up often. It is also disruptive to have your absences occur at key moments when you said you'd do something but were unable to follow through.