Spending quality time with each child alone

I would love to hear some ideas of what you moms do to spend time with each child. Sometimes I take my kids out of school (at different times each)  at lunch time and take them to the local pizza or bagel shop. Any other ideas? My kids are 7, 6, 3.5 and 15 months. So I just need for the first 3. The baby is home with me. But my mom comes a lot to watch him so I can do things baby free.