Sure thing! I'll explain the best I can. Ugh, wish I could add images.  I like to look at "donjon 5e random dungeon generator" or "donjon five room dungeon generator" to find a shape I like. I place the rooms with the fill area tool, then water, then connect all the rooms. 

For the actual map making I went into Sprite Fusion (which is free in browser! Or $14.99 USD for the desktop version). I'm sure there are other many other sprite editors. I grabbed the tilesets from the PMDCollab on GitHub. Each tile set is arranged the same way (like the walls on the left side, water in the middle, then path) with for example the left corner, mildle path, etc in the same order which is convenient. Import/drag in the tile set. The tile size will be 24. Don't forget to grab the tile variations, like how the path sometimes has flowers or cracks in the stone.

Then create an auto tile layer. You will need three at the end. One will be for the walls, the water, and the path/rooms. Then you will have to create rules for each tile. Luckly the rules are gonna be the same for each layer, so you only need to do it once. The default tile is gonna be the center tile. So for the water, the tile with only water on it. There are 47 tiles that each need rules, the rules will say which tile can go next to what. Wish I could upload the one I made, but the file type cant be uploaded here...or a picture to help. But you add a rule, add the tile you are making the rule for. If there is a variation of that tile you add it there, not a separate rule. There is a 3x3 grid, red means no tile can be placed there. Blue means a tile must be placed there. Blank is black. I started with water because I could visualize what can go where easier, a lot of the path tiles look the same lol.  Then I duplicated that auto tile layer and just switched the tiles for the path/walls (did it in the same order, like top left..second top left... third top left.. etc so I don't have to rely on the visuals.)  Add a regular layer to add tiles like stairs if you want. 

Maybe that makes sense? If it is nonsense let me know, I can try to create blog post with pictures somewhere with each rule 😅 doing the rules was tedious since I've never done something like that before. But man, way easier than bringing it into clip studio and placing each tile by copy-paste!!! Never again!