I just figured out how to to cut long, curly hair

tldr: You have to hang your head upside down. Let your mane fall naturally with gravity. Take note of the shape. Run your fingers through and feel the long areas – usually the sides and/or back grow faster so those are the areas that need to be trimmed to give the mane a nice, smooth shape.

Full article:

Wash your hair and condition your hair the night before as you normally do. Do not use any gels or styling products (other than leave-in serums if you use any). (Lately I’ve been using Davines This is a Curl Building Serum which I really like. Only use very small amounts – a little goes a long way!)

The next morning turn your head upside down and run your fingers through your mane. Keep running your fingers through it in case there are any (hopefully not if you care for your hair well) tangles that need to be worked out.
When your mane is fully untangled and hanging upside down, run your fingers through it and feel the shape. It is longer in one place and shorter in another? Ideally you want it to have a proportional, smooth shape.

Find the disproportionately long areas that you want to trim by running your fingers through. For me this is usually the sides near the back where the hair grows faster. Hold each long section between your fingers and turn your head back upright. With your other hand grab your scissors and clip the section you are holding.

As a rule I never trim more than about one inch at a time. Work gradually. Always err on the minimal side. You can always cut again later.

When you’re finished clipping turn your head upright again. Dampen your hands with warm (I think warm is important, not cold) water and scrunch it into your ends again to reshape it. You can turn upside down and scrunch more to induce volume.

At this point your hair should be shaped and falling the way you want.

It is a process, but you have to work with your mane’s natural shape. Because hair grows faster in certain areas so you will know which areas usually need to be trimmed regularly.

If you use a lot of serum the night before, when you’re scrunching the warm water in your curls you should rinse off any excess product residue that accumulates on your fingers, otherwise you will just keep respreading it through the hair.

For styling my absolute favorite products are Kenra Daily Provision and Kenra Frizz Control Primer both of which I use on dry hair.