Example of how i draw the awesome Array/List inspectors in the swindle

gistfile1.cs

  public override void OnInspectorGUI2()
    {
        // First off, cache a copy of target cast to its type, makes like easier. EXAMPLE
        AmbientLight light = target as AmbientLight;

        // This is to top area of the inspector GUI. draw controls here for making chages to parts of the target object that arnt part of the array. 
        light.timeOfDay = EditorGUILayout.Slider("Time of Day", light.timeOfDay, 0, 24);
        
        // leave some space to split the main settings from the array
        EditorGUILayout.Space();
        EditorGUILayout.Space();

        // this lays out the toolbar above the list
        EditorGUILayout.BeginHorizontal(EditorStyles.toolbar); // pass the toolbar style in to the EditorGUILayout. this makes it look about a million times nicer!
        GUILayout.Label("Colours"); // This Lable acts a a itle
        GUILayout.FlexibleSpace(); // this eats up all the left over space, and pushes the buttons were about to draw to the right of the tool bar
        if (GUILayout.Button("Clear", EditorStyles.toolbarButton)) // Use the ToolbarButton style on buttons to make everything look ace
        {
            // array clearing logic...
        }
        if (GUILayout.Button("Fill with sample colours", EditorStyles.toolbarButton))
        {
            // fill array with sample data...
        }
        if (GUILayout.Button("+", EditorStyles.toolbarButton))
        {
            // logic to add a new entry to the array
        }
        EditorGUILayout.EndHorizontal(); // end the toolbar

        EditorGUILayout.BeginVertical(); // begin the list here! You could also use a scrollview if you had lots of data in your list... for example....
        //EditorGUILayout.BeginScrollView(scrollPosition, GUILayout.MaxHeight(400)); // the max height lets you contorl how big it gets to be
        if (light.dayColours == null || light.dayColours.Count == 0)
        {
            EditorGUILayout.LabelField("No colors, add some data");
        }
        else
        {
            // keep track of adding/removing entries 
            bool remove = false, addUp = false, addDown = false;
            int index = 0;

            for (int i = 0; i < light.dayColours.Count; i++) // do a for loop over your list
            {
                EditorGUILayout.BeginHorizontal(EditorStyles.textField); // This horizontal area encapsulates the whole entry. Use the text field style to gice it a nice background.
                EditorGUILayout.BeginVertical();

                EditorGUILayout.BeginHorizontal(EditorStyles.toolbar); // start the toolbar at the top of each entry
                // you can use a Label here if you wanted a title for each entry
                GUILayout.FlexibleSpace(); // eat up some space untill we draw buttons

                if (GUILayout.Button(" - ", EditorStyles.toolbarButton)) // draw a button for deleting this entry
                {
                    remove = true;
                    index = i;
                }
                if (GUILayout.Button("+ ↑", EditorStyles.toolbarButton)) // draw a button for adding a new enty above this one
                {
                    addUp = true;
                    index = i-1;
                }
                if (GUILayout.Button("+ ↓", EditorStyles.toolbarButton)) // draw a button for adding a new entry below this one
                {
                    addDown = true;
                    index = i+1;
                }
                EditorGUILayout.EndHorizontal();  // end the toolbar

                // draw the entrys content here!

                EditorGUILayout.EndVertical(); // end the entry box
                EditorGUILayout.EndHorizontal();
            } 

            // the List/array has been drawn! now, respond to the entry toolbar buttons.

            if (remove) 
            {
                light.dayColours.RemoveAt(index);
            }
            if (addUp || addDown)  // NOTE: ive no idea if this bit will work. In the swindle i actually sort the list based on time of day, in this example ive used insert. It should work, but its not tested. 
            {
                TimeOfDayColour c = new TimeOfDayColour(.....);
                light.dayColours.Insert(c, index);
            }
        }
        EditorGUILayout.EndVertical();// or end scroll view, if that what you used

        if (GUI.changed)
        {
            // if something changed, tell unity to save it.
            EditorUtility.SetDirty(light);
        }
    }