Ok, I got the Model D STP today and I practiced a few times in the shower and now I feel like I can pee with it. Woohoo. I will admit I'm going a lot right now because I'm scared of back flow. But what I am having troubles is positioning it and having it be comfortable and not look all wrong. Talk to me like I'm a complete idiot and give me tips please.

Not kno0wing what a 'Model D' STP is, I can't answer your questions. Do you have a link of where it is shown or sold from?

I believe this is what they are talking about?
http://www.ftmessentials.com/products/model-d-stp
Please correct me if I'm wrong.

I haven't used a stp yet, but from other's suggestions on back flow, practice kegal exercises and controlling the flow.

I'd sort of forgotten about this post. Yes hex, that's correct.

I feel more comfortable but I'm still curious if others have used it. I get the stand to pee part (except for a bad incident that shall remain nameless) but I'm still trying to figure out how it should hang and the stupid strap I got sucks.

My friend recently bought this one, while I ordered a peecock just last week.
The model d is really firm, and from what I know, his balls stick out? if that makes sense. maybe he's wearing it wrong. I can get him to sign up to here and answer some of your questions you may have. Though he is also still new to it.