When you first began wetting your diaper (if you did. I know some wear diapers because they like to, but seldom, if ever wet them. And that is fine by me.) what helped you start the flow?
For me it helped to be standing and hearing water flow from a faucet. Now, I can go anywhere I am, even lying in bed. It is a matter of convincing your body it is ok to go when you are standing or sitting in the bathroom. It won't be long before you go just about anywhere, in any position - and it won't make you imcontinent. Just be sure you are wearing that diaper before you let go!