First, i throw in a 1:1 ratio of Epson : Dead Sea salt into the drawn bath water.
Then into the salted water I pour in my bath mud, which is homemade LS that I mix w/ olive, jojoba, chia, argon, hemp oil. The soap eats the oil and turns into a nice mud, which together w/ the salts help soak up the essential oils you add next. Ba sure to use MORE liquid soap and less oil. If you use more oil than soap it will be a solid rather than a nice pourable liquid of honey-like consistency plus the bath water is a bit oily.
I a small mason jar, mix a 1:1 ratio of essential oils : carrier oil. For carrier oil, I like to use chia seed, argon, jojoba, or just olive.
Then hit the oil globules w/ a small cotton wash cloth just skimming the surface. Making bath salts is way too much trouble.
It is basically this product but I leave out the baking soda and use 100% salts plus a little powdered lactose and Meyerson's powdered goat milk. You can mix this all up in a mixing bowl w/ some citric acid if you want and fill it into a mason jar. But it leaves your kitchen messy and takes alot of time. I find it easier to add each ingredient to the bath separately.
http://www.essentialwholesale.com/product/1122/goat-milk-bath-soak
You don't have to rinse this bath water off. Just blow-dry yourself dry bc your whole body has oils on it and otherwise it will take longer to dry. I love to blow dry my feet and arm pits when I get out of the bath w/ a high-powered negative hairdryer. A hair-dryer is a power tool and the good ones run you $65 - $200 but they last a few years and are worth it.