Derive from this class to create an editor wizard.

// C#
// Creates a simple wizard that lets you create a Light GameObject
// or if the user clicks in "Apply", it will set the color of the currently
// object selected to red
using UnityEditor;
using UnityEngine;
public class WizardCreateLight : ScriptableWizard {
    public float range = 500;
    public Color color = Color.red;
    
    [MenuItem ("GameObject/Create Light Wizard")]
    static void CreateWizard () {
        ScriptableWizard.DisplayWizard<WizardCreateLight>("Create Light", "Create", "Apply");
        //If you don't want to use the secondary button simply leave it out:
        //ScriptableWizard.DisplayWizard<WizardCreateLight>("Create Light", "Create");
    }
    void OnWizardCreate () {
        GameObject go = new GameObject ("New Light");
        go.AddComponent("Light");
        go.light.range = range;
        go.light.color = color;
    }  
    void OnWizardUpdate () {
        helpString = "Please set the color of the light!";
    }   
    // When the user pressed the "Apply" button OnWizardOtherButton is called.
    void OnWizardOtherButton () {
        if (Selection.activeTransform == null ||
            Selection.activeTransform.light == null) return;
        Selection.activeTransform.light.color = Color.red;
    }
}