Update DOCUMENTATION.md

Author: Fernando-A-Rocha

.github/doc/DOCUMENTATION.md

@@ -71,6 +71,18 @@ Check the [`meta.xml`](/newmodels_azul/meta.xml) file to see the exported functi
 Example usage:
 
 ```lua
--- The normal createVehicle would not work invented IDs such as -2
+-- The normal createVehicle would not work with invented IDs such as -2,
+-- so we call the available exported function
 local vehicle = exports['newmodels_azul']:createVehicle(id, x, y, z, rx, ry, rz, numberplate)
 ```
+
+## Important Tips ⚠️
+
+These are good practices and general advice.
+
+- Remember that your models must work well with GTA: San Andreas in terms of optimization.
+- Always with several players and PC specs.
+- An element created serverside with a custom model will sync its custom model to all clients.
+  - Useful for spawning vehicles, setting player and NPC skins.
+- An element created clientside with a custom model will not sync to other clients, meaning only the client that ran the code will see the custom model.
+  - Useful for model previewing and object spawning which works best clientside.