I would do a toothepick trial, dip the ends of a toothepick in the E.O. (the way people describe to do it with a qtip) and then a different toothepick in other E.O.'s. One toothepick per part so if you are going to do a 1 part ylan with three parts lavender, do one toothepick ylang and three toothepicks lavender. This website has blend suggestions on it, https://www.mountainroseherbs.com/products/ylang-ylang-essential-oil/profile