I'm not known for having the best memory. It is important as a youth pastor to know who are your team will be at your youth group gathering so you are prepared.
Our system used to be "tell Andy" if you aren't going to be there. I would then promptly forget.
Our system changed to "give Andy a written note" if you aren't going to be there. I would promptly lose the note and forget.
Our system changed to "send Andy and e-mail if you aren't going to be at youth group". I would get the e-mail, read the e-mail, then forget.
Our system is currently The Planning Center an online tool to use to schedule your church's teams for ministry. I love it! I can simply log on and at a glance see who is going to be at Contagious on Sunday night. Team members can block dates. I can schedule out as far in advance as I want. An excellent tool.
We use The Planning Center for several teams in our church and are slowly transitioning all our teams to The Planning Center. With the teams I am responsible for I have around 30 or team members to schedule. The planning center has relieved many of the stresses and frustrations of scheduling. PLUS it helps with my "memory".