If you are going to be applying larger pieces of monokote over monokote using the windex method is about the only way to do it so that you don't get air bubbles trapped under the monokote. It's really a pretty easy process to do. Check this thread out for detailed instructions on doing it:
[link=http://www.rcuniverse.com/forum/m_603331/anchors_603331/mpage_1/key_flag/anchor/tm.htm#603331]Applying monokote graphics with windex.[/link]

It does help to go over the edges after you are done to ensure that you have a good seal that won't lift up. Many will use the trim solvent designed for Monokote to seal it down. But I have found that using a small trim iron, or the tip of your regular covering iron, will do a good job of sealing down the edges.

Hope this helps

Ken