@shadefoundry You've got the shape of it right, I think, so that part is looking very good. The double outline is not a good way to go. Right now because of a quirk of the colors you used it's got this strange double image thing that it's doing, like the second outline is actually a strange problem with the monitor it's being displayed on or something. It's creating a blur, but not in a good way, in a way that's uncomfortable to look at. That's hiding the problems of doing a second outline all 1:1 like that and it would show up more once you change colors. Think about what you're representing with that outline and what characteristics that thing is going to have. Is it the beach? Beaches aren't uniform, in some places they're thick and some they almost don't exist. Is it grass right up next to the edge? What would the edge of grass look like then? What colors would best show what you're trying to represent? I realize that some of these problems are from the way you're doing the corners since the more dynamic you make the edge itself, the harder it is to hide how square the corners are, but I think there's a better compromise to be found if you work at it.
@KaBlooZio I think you'll be able to get the hang of it with practice. Hmm, maybe this would help. When I was first learning pixel art, specifically how anti-aliasing worked, I would draw something in a program with the anti-aliasing turned
on, like a line or a circle or squiggle, and just study it to see how it made things look smooth without making it also look thicker. I noticed that parts of this are because of the shade variation in both the inside and outside of the line, which you can't always do in pixel art due to transparency, so that part is not necessarily useful right now. For this particular problem I think you need to ignore the inside of the line's shading (at least at first). If it helps, draw the line anti-aliased and then again exactly the same but without anti-aliasing, so you get a good look at just the exterior anti-aliasing, where and how much shading each segment gets. You could even reduce the colors so you can see it more clearly.
and these being so small, 16x16, I find it difficult to avoid dithering
Wow, I really don't get this! There's so much less room to put any dithering in!
Something that I've noticed is that dithering is really useful in hiding problems. Because of this people get the incorrect idea that putting in dithering is
solving a problem that they can't define. If the edge between colors is too hard you've either put the shadow (or highlight or whatever) in the wrong place or you've chosen the wrong colors.
Like I said, sometimes it's the right choice, but I think you'll improve faster as a pixel artist if you learn how to make a piece work without it first and then strategically add it back in.