The only consistent thing that I can think of is permanent employment. Anything else is subject to change.
Here are some suggestions:
If you have school age children, consider working as a classroom aid or in the cafeteria at their school. You're only at work when they are at school and you have the summer off.
If you have a college degree, consider tutoring students in an area that you excell in. Students especially need help with math and reading in the early grades. Older kids often need assistance with science and math courses. Tutors in our area get $15 per half hour and sometimes more if they have to travel to your home.
Consider doing housecleaning or running errands for an elderly person in exchange for a fee. You may be able to make contacts through your church. With so many families living a good distance from elderly parents, this type of service can be of great benefit.
Babysitting isn't just for teenagers anymore. Especially when both parents work and cannot be home as early as school lets out. In our area, afterschool programs have waiting lists a mile long and I know of kids as young as the 3rd grade who come home to empty houses. I'm sure that their parents would be willing to pay a few $$ just for the peace of mind it brings to know that their child is being supervised by an adult.
If you sew, offer to do the patches for local boy and girl scout troops. I remember one mom in our Brownie troop who used a hot glue gun to put her daughter's patches on her vest! Not only did it look bad, the patches fell off easily and got lost. Most busy moms are willing to pay a nominal fee to get this annoying task taken care of properly.