AROMA SHAMPOO 
Start with a base, then you add your essential oils according to what you want for your hair. grapefruit (and other citrus) : if you want to add shine 
basil : if your hair is dry (go easy, basil has a very strong aroma...not pleasant)  
geranium : for dry hair  and so on... 
for my small bottles of shampoo and conditioner, i use the following: you can add and subtract as you wish...  warning: this shampoo does not lather much, so if you like to get sudsy, you  won't care for this.  
15 drops geranium  15 rosemary 6 lavendar 6 peru balsam 5 basil 6 pink grapefruit 2 chamomille 2 primrose 
conditioner: 2 sandalwood (i add more because i LOVE the scent) 2 balsam 10 lavendar 3 primrose 3 carrot 3 chamomille 4 orange 6 rosemary 6 geranium