Two Tool I Like for Creating AdWords Campaigns on the Google Display Network

1. Google Web Designer for creating HTML5 ads.

Description

Google Web Designer is a program for Windows, Mac and Linux from Google for creating interactive HTML5 ads and other HTML5 content. It offers a GUI with common design tools, such as a Text tool that integrates with Google Web Fonts, a Shapes tool, a Pen tool, and 3D tools. Source: Wikipedia

https://www.google.com/webdesigner/

2. Unbounced for creating Landing pages linking to my ads in the Google Display Network.

A landing page is a page on your site that is designed to convert visitors into leads. A landing page is different from other pages in that it follows both of these criteria: It has a form that allows you to capture a visitors information in exchange for a desired offer. Source: Wikipedia