I used to use Dr. Bronner's, I've since switched to the Dreadlocksshampoo.com products. For Dr. Bronner's a 1:12 ratio is a good place to start, the only problem is I find it takes a lot of water to wash out. My own recipe for an 8 oz (237 ml) "spray bottle" was 1 Tablespoon of Dr. Bronner's Peppermint & 1 Tablespoon of Dr. Bronner's Eucalyptus with 2 Teaspoons of Sea Salt. Two Tablespoons (29ml) total of soap to 8 oz (237ml) of water is very close to 12%, again a good place to start, but some find this ratio leaves their hair feeling too heavy so you might have to play with the formula and dilute it further like Soaring Eagle suggested.
Since your dreads are just starting out I would also add Sea Salt to the mix as I used to, use only a 3-4% salinity just like the Ocean. For an 8 oz bottle that is only 2 teaspoons of Sea Salt.
The Baking Soda & Apple Cider Vinegar rinse is good to do once a month to really deep clean the scalp & dreads and get rid of any deep lingering funk before it becomes a problem. Remember to boil the water first, it helps. Leave the ACV in a good long time so that it really soaks to the center of the dread, this helps bring the hair's pH back to normal and strengthens the hair. Here's a link to a really good discussion on proper ratios:
The best advice I can give you though is keep the Dr. Bronner's and use it as a body soap and use the Liquid Locking Up Shampoo from the Dreadlocksshapoo.com site. I've tried them ALL, from Jamaican Mango & Lime, Knotty Boys, DreadheadHQ, Dr. Bronner's, and smaller local vendors. I can say from experience that the best hands down are the small batch Artisan made products made by Vicki, no other products even come close. She really cares about giving us the best made products with the best ingredients like using Himalayan Sea Salt in her formulas. They rinse out really well and boy do they smell great. Honestly I wish I had started using her products sooner. Here's a link:
I like to use the Locking Up Sea Salt Accelerator spray as well in-between wash days, Vicki adds Icelandic Kelp and other plant based proteins to help strengthen the hair.
Lastly head out the beach. Swim, surf, free dive, anything as long as your in the water. Ocean water is the best for frizzing up & locking up hair. It'll be all poofy once it dries before they start to mature so take a bandana if you don't like to rock the beach head look.
Good luck and blessings on your Journey brother & keep us posted.