Honestly, pay a queer stylist to do them and explain what’s going on. They’ll be way more helpful than folks here ;)

If you can afford it, going to see a professional can be an amazing experience. With eyebrows having nice full brows is actually an advantage, it leaves way more options for shaping them. I definitely recommend looking into threading them. There's also tinting and laminating, which aren't necessary but can help a lot.

With threading, a clearly defined shape will be created, but they will consequently be much narrower, and depending on color and density, it can have a too light appearance. In that case, tinting can be a great option to keep the edges nice and defined. May not be an issue for you, but I think it's good to know what your options are.

Brow lamination, not related to paper lamination lol, is a treatment applied to your brows to keep the individual hairs pointing in an upwards direction, as though they have been brushed that way. It's not something I'd worry about unless you want to save time doing a makeup routine, but it is an option you'll see offered at a lot of places. If you check out before after pictures, you'll see the effect it can have.

Hello there! :) I'm a cis guy, so maybe not the very best source, but honestly i would search online for a nice spa where they offer waxing or something like that and just have a nice day there, and ask for advice from the staff there what would look good on you. And also maybe some ecosian and pinteresting? I guess there are a lot of examples. Maybe even some drawing guides to see what effects different shapes have? I hope this gets the ball rolling, and hope I did not overstep any boundaries

Good luck on your journey! :)

I found an amazing queer salon near me. They are fabulous and exactly what I needed! Came to them when I wanted to try my first femme cut and they walked me through it all. So next time I'm going in I'm having them wax my eyebrows for me. They know I want something feminine and to fit my face but I trust them to know when to use their professional discretion and when to ask for my input ❤️

Maybe look for a queer or trans allied salon you can go to? They can be expensive, but worth it if you find the right one.

I use this guide for shaping my brows.
Try to get some eyebrow scissors and if you can an eyebrow brush. Use the brush (or your fingers) to hold them pointing straight up, and cut the hairs to the top of your brow. Also, only pluck from the bottom!

When you're ready to make big changes, definitely look into threading as an alternative to waxing, a lot of folk find it less painful in the long term. (But it still really stings at first! :) )

Having thick/full eyebrows can be an advantage, since you have more to work with. I have the problem that my upper eyebrows are a bit too sparse, which makes them much more difficult to shape.

I would opt for subtle changes over time. It's up to you, of course, but I had some success tweezing my brows gradually. After months, they were quite a bit thinner, but not "weird" and it wasn't a sudden drastic change that would draw attention. But indeed I propose talking with a professional who does this every day for a living.