This is a big question, honestly. I’ve been mulling about how to answer this for quite a while, because I don’t see myself as a person with enough skill to actually teach. That’s a bit boring, though, so I am going to do 2 things. First a quick step by step on the basics of how I do currently, and second some talk about my inspirations and people who I look to for learning.
This is my basic approach. 1) I block in the shape. Note that I use a colour very close in value to the skin. 2) Pick a colour and block in the iris. My brush is set to have a bit of oppacity variation on pressure, so this is slightly lighter than the picked colour. This is important for:3) With the same colour and brush, I outline the iris and draw in the pupil. 4) Again, same brush and colour, I add a shadow from the eyelid. Its important to think of the eye as a form and not just a sticker plastered on. This helps show that. 5) The funnest part - I put in some spot highlights, accounting for where the lightsource is. Now, the real thing is that to draw eyes you kinda need to understand how the eye is build up. There’s a lot great resources talking about this. I’ve been refering to Sinix video on eyes (This whole series is really good) as well as Doxy’s notes (Which I’ll also generally recommend, as they are a treasure trove of neatly condensed and helpful information. Find ‘em here.)The thing is, though, reading tutorials isn’t enough. I will always recommend 2 approaches before or after you’ve read a tutorial on anything art related. Both deal with putting it to practice. 1 is *drawing from real life* and studying the thing in question. Not just in pictured (where possible), but actual life. Bring a sketchpad and draw it, again and again. And try to understand why it is the way it is. Use a mirror if necessary, to study your own face and eyes. 2 is looking at art that does the thing well, and trying to figure out *how* it does that. And tryinng to copy it. Not tracing, but analysing it and trying to replicate its result. Tutorials and speedpaints help here, but remember that actually drawing the thing is what builds skill. Always ask yourself if you wouldn’t gain more from just trying to draw it. Some wise dude once said that drawing is 10% theory and 90% practice (or around that), which I very much believe in. This got rather long. I hope this is useful in some way for you. Thanks for the question, and for reading if you’ve made it this far! I’ll get out of y’all’s feed now.