I've made an essential oil mixture in a bottle for scalp massage, can I vary the amounts of it I use each time?

I've made an essential oil mixture in a bottle for scalp massage, can I vary the amounts of it I use each time?
It would depend on what kind of essential oil you used, some are much more powerful (and potentially toxic) than others. For something like lavender, which is pretty safe, you can vary how much you use.
Eg Should i use 20ml each time or can i use 5ml then 10ml or even 50ml. Doesn't it matter as long as the dilution is ok?

---

Orignal From: I've made an essential oil mixture in a bottle for scalp massage, can I vary the amounts of it I use each time?