Making your own tea blend Tips

I always see such creative blends in holistic shops or spice shops. I am curious how people go about learning what works and what doesn’t work with what types of tea. Are there is YouTube videos / books that help learn to start creating your own tea blends? I feel like the best way to learning is only working at these shops or trial and error. I’d appreciate any recommendations on books or videos to start learning some loose leaf blends to make at home.