It's generally a tablespoon of vinegar (people often adjust that up or down a little) in a cup of water. I use a big mason jar so I do a little more water and vinegar - I soak my ends in it for a minute then just pour over my hair and rinse it out.
remember, with all advice or suggestions for your hair, YMMV!!
My hair:
2b wavy, medium texture, low porosity, med-high density. Protein finicky.
My routine:
Cleansing: DCNP, every 4-5 days (occasionally use CJ cleansers).
RO: CJSC, occasionally use JCDC
Gel: KCCC, CJCIAB for 2nd day hair (sometimes third)

Heat is my friend: warm water rinses, steam caps, and diffuse dry. I love CLU cloths and my Denman.