If you're talking dungeon design and conceptual layouts, best way to design one that I've found is using a good old-fashioned
Concept Web.
Write down a list of cool elements you want in the dungeon, like specific traps, challenges, thematic places, and so on. Include things like "Entrance", "Miniboss", "Healing Shrine", or whatever in the list too. Once you have your concept list, arrange these elements in a conceptual web, with lines representing how the places or elements are connected to one another. Generally you want to make visually interesting elements that are relatively non-challenging as a Hub and rest-space which that connects individual challenge rooms, and these challenges should stand between the hub and some sort of objective or reward (a tool or switch that allows further progress, a useful utility, an interesting plot element, or something otherwise rewarding). You'll want to create barriers between hubs and challenges as well; perhaps a barrier between hubs that can be opened with a switch that follows a challenge area, or which can be bypassed with a tool you have to go get (a waterbreathing helmet to survive a water tunnel, a diamond pick for obsidian blocks, etc).
Once you have this web done, start to lay out how the rooms will actually be connected and divided. The areas could have physical walls between each, or other barriers, such as ladder-scalable cliffs, etc. Note that a high-up bridge over an older area can connect two new elements of the dungeon, and provide a new view of a visually interesting area the players visited before, without being accessible from below. The possibilities are endless!