I seem to remember that I bought two boxes of washable breastpads last time I was pregnant. They were around £6 per box and contained 6 pads. They weren't that comfy and despite being shaped they were still noticeable through my clothing. They also didn't have a waterproof layer, so when I leaked a lot when out I still ended up with a wet t-shirt. I figured that I could do better than that so have experimented with making my own. When you think about it, a breast pad is only a circular pad of fabric, so shouldn't be too difficult to make!
I used offcuts of material left over from other projects, hence the bright yellow waterproof cotton, but the cost is £0.
As they get tried and tested I will post updates of their performance and washability. I used two different fabric combinations to start off with.
The different types of breast pads are constructed in exactly the same way, it's just the layers of fabric that are different.
One type has three layers of cotton flannelette and a layer of fleece, so that I can see if the fleece will act as a waterproof barrier on the outside and also, if I wear them the other way, to see if they are more comfortable should my nipples get sore. A bit like having a fleece nappy wrap or a fleece nappy liner! 
The only difference is that I used a slightly smaller template. What I realised is that when I shaped two of the pads they ended up significantly smaller, so use a larger template when making shaped pads!
The main type I made have 4 layers of flannelette (left over from the nappies) with a layer of waterproof cotton (the bright yellow fabric!) and a layer of cream polycotton as an outer. This outer layer is not necessary, I just used it so I didn't end up looking like I had a couple of fried ostrich eggs down my top. 
Layer the fabric so that you have your waterproof fabric on the bottom, with the waterproof side (usually feels rubbery) facing upwards, then lay your four layers of absorbant cotton on top (in this case the left over nappy flannelette) - if you are having trouble finding waterproof cotton you could use an old fabric shower curtain, I normally use this for bib backing. 
Pin through all the layers of fabric around the edges so that the material doesn't slide about.
Select your template - I used a size A (11cm diameter) tupperware bowl - and draw as many circles on your fabric as possible.
Using a contrast colour thread to baste (tack) around the inside of the circle you have drawn
Cut around the circle, being careful to avoid the pins and to cut through all layers of fabric.
Using a zigzag stitch on a regular machine, or an overlocker, stitch over the edges of the pad. Remove the contrast coloured hand stitching.
Repeat this procedure on all of the pads. You should end up with quite a few!
These pads are unshaped (i.e. they are flat) like the majority of disposible breast pads used to be.
To shape the pads you will need to fold the pad in half, with the absorpant cotton on the inside. Then using a running stitch (-------) sew from the centre of the pad on the fold to the outer edge of the pad about 1cm in from the seam. Trim the excess triangle of fabric away and open out the pad, it should now be slightly conical. I then used the zigzag stitch on my machine to sew over the seam, to reinforce and flatten it.
Hi again,
Do you think its a good idea to shape the breat pads, or doesnt it really make any difference?
Thanks, Paula