One of the best resources I found when starting to use tarps as opposed to the old issue poncho was the tarp and hammock tutorial found here:
http://www.bushcraftuk.com/forum/showthread.php?t=53500
I can't fault the setup in any way and I'm yet to better it really. The only thing I do differently is set my tarp up like this when I require full side protection:
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I use a 5 mm bungee as the only guys (one on each side). As you can see from the photo, it creates a wider area in the middle of the tarp which I find useful for getting in and out on my hammock, although this may not be of use to yourself when using the poncho tent.
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This one shows the inside of the tarp (albeit with the hammock obscuring most of the view) but you get the idea with regards to the wider central area, and how it benefits hammock dwellers like myself.
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Finally, in comparison the the DD 3x3m tarp; currently sported by Oakhill Wanderers setup on the left.
Sorry about the quality of the pics (courtesy of the carp camera on the Iphone
)
In my opinion, if there's only one thing that will make your setup easier; it's the Prussik knot. It's simple and highly effective for keeping the tarp taught along the ridge line.
I hope this helps.
Steve