As you can imagine, it can be hard to keep things such as mala beads when living in a christian household. I've found this is an effective way to keep count.
https://western-hindu.org/2010/01/01/how-to-chant-a-mantra-108-times-without-mala-beads/
https://western-hindu.org/2010/01/01/how-to-chant-a-mantra-108-times-without-mala-beads/