Well see I tried those ones out and I got some really funky result out of it, like the tiles don't line up at all, and they don't really seem to be like the kind of tiles that most people are normally used to. Was it because of the way I resized them, or what? Also the images seem to be working fine; it's a tileset. What kind of method should I use if the resizing of the image is the problem? Because most of those tiles I have already tested out on almost all of the different types of mountains and for the most part, they give really bad results.
For anyone else reading this: For the resizing, I did what everyone tells me to do with it, and I double the size of the tiles so that they are RMXP compatible.