So now you've created an awesome map, it has amazing lazer puzzles, guards patrolling every inch of your map and a ♥♥♥♥load of loot. What's next? Well, your map will probably feel very unfinished for a player at the moment. That's because it's ugly! Yeah, i said it! Your map is ugly! But don't worry, making your map very pretty is easy and a lot of fun!
Ok, maybe I haven't been completely fair, your map probably isn't that ugly. By now you should have a lot of different items to place on your map and make it quite pretty already. In the Item layer you find several Decor folders and there are tons of items there to increase the visual appeal of your map. Maybe something you have missed: There are also quite some useful tiles in the Furniture layer. Especially the Sculpture and Misc folder are very useful. The Misc folder contains several items that you might expect in the Item layer, so check them out! Also you should combine some of the items in the Furniture layer with the ones in the Item layer. For example: You can place a lot of things on tables or shelves (especially jewelry behind glass should be placed on tables, otherwise you'll get weird AI behavior). Another nice combination is the Shelf Box and Shelf Plant (in the Shelves folder) in combination with plants from the item layer. This way you can create all kinds of potted plants. That should be enough about the several items you can find in the editor. They are mostly self explanatory.
Now lets talk about lighting. You can find a lot of lighting items in the Ambient Lighting folder in the Meta layer. There are 3 kinds of lighting in there: Dimmed lights, Line Of Sight Lights and special (flashing) lights.
The dimmed lights can be used to set atmosphere. They are not affected by walls and just create a small amount of (colored) light. You can experiment with these a lot as they aren't as obvious as LOS lights and they can sometimes create very dynamic and visibly pleasing levels. Note that there is a tiny version of the white dimmed light.
The Line Of Sight Lights or LOS Lights are affected by walls, which can create very nice patterns. If you want to create a "normal" light in the ceiling, you can just use the white (or sometimes yellow) light. Using colored LOS Lights is easily noticed by the player, so be careful with them.
There are also a few special lighting tiles in the Ambient Lighting folder. The CrystalLight, WaterLight and PulseRedLight are pulsing lights in a certain color. The two dance floor tiles are used for creating flashy dance floors. If you place a few in a row, you will create a running light. The difference between the two dance floors is that the left one looks a bit smoother than the right one.
There is also a second folder with (even more) lighting: in the Item Layer in the Lights folder. These are all visible lights, like street lights, candles, neon sign boards and more. Just look through them and you'll find a lot of cool things. I will mention two special ones briefly: BigWhiteLight is a chandelier that actually hangs from the ceiling, characters will walk beneath it. The LightProjecter can be used for a small cinema or for people giving a presentation.
When you're creating a map with multiple floors, you sometimes want to add lighting later, but your lower floors are incredibly dark, since there is no lighting yet. There is a solution for that: You can turn off lighting in the settings. You can also toggle this feature by pressing L on your keyboard (Nothing for controller users here). If you turn of the lighting, everything will appear as if there are a lot of lights shining on them. So everything should be visible. Note that if you do this, lasers won't show! So creating traps is hard and you probably want to enable lighting for that. Also you can use M to toggle the meta layer to always on or normal mode, which might come in handy from time to time (you can also see the meta layer if you have any folder in the meta layer selected).
Also important to note is that some windows will create a beam of light that looks like it's coming from outside. You can find two StainedGlass windows that do that in the Lights folder, you can find even more of them in the Window folder in the Item layer. Note that there aren't a lot of differences between these stained glass windows, except if you look at the sideview of your map. Also, since we're talking a bit about windows now, you can find the window you can climb through in the Window folder, it has the name WindowOpen.
Weather and background music
If you want to change the lighting outside you probably want to do that by changing the weather. In the Environment folder of the Meta layer you can find the different possible kinds of weather in the editor. They are classified by the level of the original campaign that they're in. Just try a few and you will see the result immediately. You might have noticed this before when you were constructing multiple floors, but if you place something on the floor above another one, it will cast a shadow. This means you should place some floor tiles directly above your highest points of your map if they are supposed to be inside. Otherwise the lighting of the weather will be visible indoors, which looks weird. One of the consequences of choosing a type of weather is that the background music will change. Every Environment tile has it's own weather and own background music, which are both connected to the original campaign. You can't hear the music in the editor, so you have to try this or take a look at the original campaign levels.
You might have noticed sometimes that there are some special sounds in monaco. For example you hear people talking, you hear music pounding, water drops in a cave and a lot more. Most of these special sounds can be found in the Ambient SFX folder in the Meta layer. You place them on the spot you want the sound to come from (so if a player gets close, he will hear that sound). Don't place the same sound multiple times close together, it will only create a lot of noise and the player won't recognize what sound it is. Sounds have a certain reach (depending on the sound) and only 5 sounds can play at the same time, so be careful. Some items make sounds of their own, this includes guards but also civs. So be careful with the Murmur tiles as the civs will also talk and sometimes that is enough.
You might have noticed that there are in-game texts from time to time in Monaco. There are two types of these: blueprint texts and hint texts. Both can be found in the Blueprint Text folder of the item folder. For a text that is only visible on the blueprint, use the first 8 tiles. Texts on blueprints are mostly used for naming the several parts of your map, such that players can coordinate a bit easier. The other 6 tiles in that folder are the DecalText tiles, they are used to give people hints in what to do. They shouldn't be used to tell a story in general as this should be done in the dialogue at the start of a level. Dialogue is explained later in this guide. In the folder Decals in the Item layer you can find things like arrows, they also are there to help the player. Note that you can type in your text directly after you place the text tile, but you are limited to a certain amount of characters. You can have different text on every floor, so you can have 8 blueprint texts per floor, which can be a total of 64 if you use them on all floors. Something you might accidentally do is placing these texts on top of other items. Remember that they are in the item layer and if you place them on top of another item (such as a vent, which I did quite often), the other item will disappear. You can use the following commands carefully: /hold_a_coincount, /hold_a_healthammo, /hold_a_objectives, /hold_lt_sneak, /move_rs_aim, /press_rt_shoot.