RBO is cheap here and I use it at 20% in my recipe.
I also go to my friends house and chop the bejeezus out of her aloe vera plant and peel it and juice it. Then freeze it in baggies. Cost = nothin' but time. That stuff grows like a weed.
I use discolouring fragrances in dark coloured soap - or in the dark sections of my mixed coloured soap. I recently made a soap with 'cotton candy' fragrance which has vanillin in it. I'm calling it 'Black Cotton Candy'
The only thing I've ever added that i found to be really exfoliating was coffee grounds ( not particularly fine ground). Everything else I've tried - pumice, sand, ground orange peel - was still too fine.
I use between 3 - 5% depending on the FO. It was only recently I noticed through a discussion on here that most people use way more than me so I have increased my usage rate. It was previously only 3%. It really does depend on the FO because, recommended usage rates aside, some are just...