One of the main stumbling blocks to good bowdrill technique is a decent bearing block. Now you're not going to find fidget spinners growing off a tree but for practise and muscle memory they are worth using..
Use which ever shape of spinner you like and shape the spindle to fit the bearing
Get your kit together and practise.. we are trying to develop a way to help people with joint problems do bow drill as assuming the form is very difficult if you have bad knees or a bad back..
The ember isn't hard to get..you can also go slightly more traditional by putting the bearing in a piece of antler
Top one was hazel on lime by Davy, second one was me with willow on willow..