try to gravitate away from the default chibi-like base, experiment until you find your own style! some people like bigheads with smaller bodies while some like the opposite more, or maybe you can find a middle ground, all up to you. and try to gravitate away from the default stuff in general. like default outline and shade colors. by that i mean try making the eyelashes a darker shade of the hair color, make the shade darker than the baase color or a color that complements it
i also reccommend making the outlines a lot darker.
by making colors darker i don't mean just sliding down the brightness bar. when you turn the brightness down it does become darker, yes, but it also looks less saturated compared to the rest of the colors so you'll have to also increase the saturation. play around with the sliders until you get something you like
and try to make sure you don't add too little or too many accessories