Unity Custom Inspector

LevelScriptEditor.cs

using UnityEngine;
using System.Collections;
using UnityEditor;

[CustomEditor(typeof(LevelScript))]
public class LevelScriptEditor : Editor 
{
    public override void OnInspectorGUI()
    {
        LevelScript myTarget = (LevelScript)target;
        
        myTarget.experience = EditorGUILayout.IntField("Experience", myTarget.experience);
        EditorGUILayout.LabelField("Level", myTarget.Level.ToString());
        
        DrawDefaultInspector ();
    }
    
    void OnSceneGUI( )
    {
        Handles.Label(target.transform.position, "Node");
        // can access handles
    }
}