Cross stitch and embroidery

Good evening, everyone!

I've done a search through this group and I'm not able to find anything on my topic question, so I'll create a post.

How do you organised your threads? I bought these plastic floss cards from Spotlight, and at first I thought they were a good idea because they'll last longer than cardboard ones, but I'm having troubles with the threads coming undone.

4-6 strands on one seems to hold well, but when there's only two, they start to unravel.

Any tips on how to manage this? Or should I start over with something else? I'm contemplating tiny pieces of painters tape to keep them together. I don't even know if I'm wrapping them correctly.

Also tried trusty Google, but I don't think I've used the right key words. A lot of results are not giving me what I need.

Thanks in advance. 🤗