ghdlfjsdf thank you!! sorry it took me a lil bit to answer, i wanted to illustrate instead of just talk cuz im not very good at teaching
anyways heres a picture of the muscles in our arms!
there are a lot of individual muscles, but i like to separate them into groups in order to simplify and stylize them cuz i use a lot of shapes to build my characters. the most important ones shapewise are your deltoid (yellow), triceps (green), biceps (orange), and then the forearm, which is just one big shape for me. heres how i usually do with my oc kat:
its basically four shapes – deltoid, triceps+biceps, forearm, and hand. i used to be terrible at drawing buff more muscular people, but i started improving a lot once i started watching jojo! its art style is SUPER over-exaggerated, but to me at least it helped point out the different muscles and what shapes i should be making, and then i toned it down and adapted it to my own art style. like, look at this wild shit (which is really good out of context):
but anyways you can see the same muscle groups, right? tone it down to something more normal-human-being and you get this:
you can see the muscle groups, and you use them as a guideline to shape the outside of your arm (which, btw, the more “bumpy/shapely” parts of the arm are on the thumb side; the outer side of the arm is smoother/straighter!), and you usually want to lightly suggest the shapes of the muscles instead of drawing them like the characters skin is vaccu-formed onto it (unless theyre a bodybuilder or theyre straining/doing something that causes the muscles to flex/be prominent, like exercising or carrying something heavy).
i also think its important to make the rest of your character proportional to their arms? like, broader chest, bigger hands, bigger thighs/legs. ofc that differs depending on how you want your character to look, but kat looks more natural to me if the rest of her is as big as her arms would suggest.
i hope this is helpful ive never rly done smth like this before hgjfsjd
I made a tutorial about mixing colors when painting! It’s really long and rambly and probably repeats itself a lot, but maybe it’ll be helpful to somebody. It’s intended for people who already have a basic understanding of color theory, so I might recommend this tutorial by gawki if you don’t already know the basics.
Good anatomical comments: wrists should be near crotch, torso is roughly two ribcages tall, hands are about the size of your face
Bad anatomical comments: “girls have smaller, thinner shoulders while males have broad ones”, “women have soft faces while mean have harsher features”, “women should have wider hips”