i think, in gerneal, your work needs less contrast. the dirt texture is nice, but the shades are rather far appart. if you were to lighten the field to be more of a mid-tone and work in some darker color as a shadow, you may find yourself with a much more pleasing textures and level of interest without being so harsh.
The grass, it is difficult to say what to do here, i cannot even really see what is going on. try using only 2 shades first, and really gettign the shapes of grass, then adding either a highlight color for hard, dry grass or a shadow color for soft, moist grass and i think you will find yourself more pleased with the result.
here are some grass tiles ive done in the past:
a less-like tileset of mine, the grass here is very simple, allowing the few details te create a real texture without being overwhelming. the drawbacks of this is that it is not completely convincing and looks like a field of needles
this tileset of mine came under harsh criticism for the grass tile's resemblance to the grass seen in Sword of Mana, a game which i was influenced by in terms of gameplay, and apparently also in terms of art (the similarities were unconscious but in the end undeniable). It is simple and fairly pleasing, but unfortunately bears the stigma of looking like a squaresoft game. it also, after a while, was not very fun to work with, because it lacks character.
not going to lie, this one is recent and SHITTY. it has too much contrast, ugly texture, and no style or character to it. I'm embarassed to post it as anything but a complete failure.
Isometric tiles are something tha i find difficult. These grass tiles (only 2 so far, lit and shadowed) though are ones that i am quite satisfied with. they are simple yet i think attractive, and so far as i know do not resemble any other specific game. They are also fun to work with, which in the end is what really matters.
theres no two ways to say it - this is just boring. nothing specfically wrong with it really, it's just incredibly boring. it needs better colors, and better shapes; really it just needs to be redone.
an oldie, it looks a bit like yours actually. too many colors, too much contrast, and not enough style. at least it tiles fairly well
well, thats all the work i can find in the few minutes i had, my furthur suggestion is to look at other people's work and stufy your pixel technique. out.
