I've just invested in an Argos value sewing machine reduced to £39.99 from £59.99 as I want to make some of my own outdoor gear.
Having never used a sewing machine before I wanted my first project to be something simple so I decided on a square tarp extension. I used 2oz proofed nylon and considereing how thin and slippery this material is the machine handled it just fine. It ended up being 10cm longer on one side but that was my fault for not being bothered to look for the tape measure properly and cutting the fabric by eye.
I have a 1.5 x 2.5 tarp and have often thought of adding some extra protection to it. The extension weighs in at approx 100g (with guy lines) on my cheap kitchen scales.
Extension laid flat.

Tarpext_0005_edited-1 by youngray50, on Flickr
Off centre porch, large side.

Tarpext_0001_edited-1 by youngray50, on Flickr
Off centre porch, small side.

Tarpext_0002_edited-1 by youngray50, on Flickr
Off centre porch open.

Tarpext_0004_edited-1 by youngray50, on Flickr
Beak.

Tarpext_0003_edited-1 by youngray50, on Flickr
The beak turned out quit a bit bigger than I thought it would. This size would be great on a half pyramid. I will add another attachment point to make the beak smaller for the A frame style.

Nice job Ray ... liking the beak, makes the tarp much more 'weather proof'.

Looks good ray. I'm liking the beak set up.
I've been tinkering with Fee's sewing machine and made myself a bivi bag. The plan was to make a roomy lightweight bag. Came in at 218g. Pertex 4 used. So not waterproof but that's ok. Cost me £10. :D

nice work fella!

i like the idea of the tarp-tent as a good compromise which is pretty much what you've created for yourself with that beak.

you used it in anger yet?

No not used in anger yet. Thinking I might make just a beak (triangle instead of square) at some point which will pack smaller and lighter. Will try 4 oz material at some point as well.
The photo's of the set up were hurried as I had other things to do so proper set up should see rid of the creases.