You can add 1-2 tablespoons of grain alcohol or isopropyl alcohol per 16 oz. of LS to thin it. Don't overdue it. While the right amount boosts lather, too much flattens it.
Another option is Polysorbate 20 or 80. Its function in liquid soap is to make FOs/EOs water-soluble. If t'were me, I'd weigh out 16 oz. or so to test. The polysorbates are best added to the fragrance before adding to the soap.
USE RATE: I use different scents for each 8 oz. container of LS. I first weigh 8 oz. into a Pyrex cup. Nuke for 45 seconds to warm it. Add 10 mls Poly to 10 mls water, stir gently, then add 2.5 mls fragrance and stir. I find that 1 part fragrance to 3-4 parts Poly is enough to get it completely dispersed into the soap. YMMV
With both the alcohol and Polysorbate, it is best to warm the LS before adding it. Wait at least an hour before deciding to add more if necessary. Allowing it to set overnight is even better.
HTH