How is a good layout made?

x made an excellent post but I just gotta chime in lol.

To me, a good layout is measured by several factors: flow, uniqueness, fairness, non-glitchiness (if that's even a word), and of course, context, like x mentioned.

Flow is how smooth the level feels overall, and how natural all the gameplay elements feel together. This can also tie in with other parts of the level; for example, if I have a song that starts out very slowly but later increases to a much faster speed, I'll make the layout reflect that using sync. Decoration can also later tie into this by how clean or messy it may be with the layout you have.

Uniqueness is, well, how unique each part of the layout is when compared to other parts. Unless context matters where the creator intends for parts of a level to repeat, I would not just copy and paste gameplay, place unnecessary portal or orb spam, etc. Even without counting triggers, there are quite a lot of different things you can do with the gameplay objects, so don't restrict yourself (unless you're making a level meant to be accurate to a specific update) in what you use.

Next is fairness - this is how fair the level is to the player and is a huge element of difficulty (since harder levels will usually be much less fair than easier levels). Stuff like this includes things like blind transitions where the player can't see what's next, the amount of time the level gives the player to react to spikes, or just tight timings in general; if you want to be fair, put yourself in the position of a player who is going blind into your level and knows nothing about it - they won't know what's after that blind jump, what all those portals stacked into one object could do, etc etc. In order to make your level fairer (if that's what you want), you'll need to do a ton of playtesting both in and out of the editor; even levels intended to be easier should probably have this done, because chances are that if there's any level you can think of where you absolutely hate the gameplay, it's probably because of one of the things I mentioned that makes the gameplay unfair. If the player dies, it should be primarily their fault, not your level's.

Now we have non-glitchiness, or the measure of how few glitches your layout has in gameplay. This also comes with a lot of playtesting; keep in mind the different jump heights and lengths of orbs and pads, as well as how things like speed changes can affect those values and how different gamemodes feel. This ties in to what I just said about a death being the player's fault; if your level has a bunch of issues they can't fix, all it will do is frustrate them, and that won't make them like the level. Even a simple thing like playtesting can greatly increase the quality of your layout, and people will probably have a lot more fun playing the finished level.

Finally is context, which may or may not be important depending on how you approach level creation as a whole. You might not care at all and just want to get your CP ufo, in which case disregard this and build whatever you want to or whatever you think will get your a rate. But if you feel a little more artistic, context in this case is what you intend the gameplay of your level to express; maybe you want your level to be fast and chaotic, or maybe slow and peaceful. Maybe you have thought of an interesting gameplay concept and want to apply it through the level, or maybe you got inspired from something in the real world and want to emulate that. Depending on what you want to convey, context for your layout can look very different, but no matter what, people who look more deeply into the creating process will appreciate your level all the more.