This is Tileset A1 from RPG Maker VX.
These are water tiles (well lava isn’t water but it’s used much the same way). I’ll set a grid so you can see how to position things in it.
Here it is. In this water tile sheet though, you’ll find that if you change the position of some tiles, it’ll change how it works. For example, I put a waterfall tile block over the bottom left side. Instead of animating like a waterfall does, it shows the first frame, then shows the next 2 water frames to the right of it. So if you want waterfalls, use them in the correct spots. 6 places for waterfalls.
You have 8 auto-tiles which have 3 of them in a row. This is for the animation. It should go from 1 to 2 to 3 and back to 2 and 1 so it can cycle over.
I made 3 16×16 water tiles, that would animate. I made the animated ones green and pink so they stand out here. Rather than make the land/water connection on top of the water tiles, I do it on the side. This is good for the water autotiles that have 3 of them in a row. I would worry about the shape of the land before you go shading it in, like making sure it tiles. Then paste it on the water. That’ll do for one of the 8 three in a row animated water tiles.
Some of the water tiles have shadows on the left side, and a floor tile (with water above) on the top row of it. You can put these in if you want. If you have a program with layers, put the water tiles on a layer above the floor tile you want to use. Then make it semi-transparent (some have it as alpha channel). I did this in Graphics Gale. Add a layer, make sure it’s in 24 bit color, then reduce the alpha to about 100. For the shadows, it was a simple reducing of brightness for the selected water, but you could do a hue shift too which would get some better results.
This is from an earlier post, but it’s still good here. See the rocks (brown and ice) on the 4th column? You can take a similar approach to this there:
This is 2x the actual size. It should be on a transparent background. Then it will make rocks over the water.
Now for the waterfalls:
I made a 16×16 waterfall tile. Then I shifted it down 6 pixels (the 6 pixels on the bottom get moved up to the top) for the 2nd waterfall tile. For the 3rd, I just repeated that process with 5. The animation goes from 1 to 2 to 3 to 1. So the reason I chose the shifting that way is because the tile is 16 pixels tall. 6 (first movement) + 5 (second movement) + 5 (back to the first) = 16. You can play around with this of course but I thought that worked well enough for me.
Then you can do the same as you did for transparent floor tiles, except it’s with walls this time. I didn’t want it transparent but you can do that. I copied the waterfall tile so there’s 4 of them in a row and 2 rows. The 1st and the 4th columns are for the sides, the middle part should repeat.
You should test your tiles out in RMVX to make sure it works as you think it does.