Step 1: To make the bra...
I chose to use stretchy fabric in a similar colour so it would match the straps. Use stretchy or jersey fabric so that it will mould round the shape of the bra.
Here I've already done one side, stage right is still to be covered.
Pin the fabric on around the edges of the bra. If your fabric has a pattern like mine, try to line the second side up with the first.
Fold the excess fabric back on itself, and then fold it over the edge of the bra. For the parts of the bra where you can't fold the fabric over, the band/straps etc, try to just pin these parts in place. The next step will be to spend a LOT of time and small stitches sewing this into place. Use lots of pins as this part is really tricky.
Ok so this bit takes ages, like hours. At first it'll be fun to do while your watching the tv, by the end you'll be having nightmares about tiny little stitches coming to get you. However, if you keep at it it'll look really good when you've finished. As you can see in this photo, the stitches at the band are pretty much invisible.
Step 7: To make the matching pants...
Choose a pair of pants that fit well and draw round them with chalk. The back is easy to do, the front will need you either to cut apart an old pair or, if your fabric is see through enough, try to sort of trace the front. Being exactly the same shape as your original pants isn't that important, mostly you want to make sure that everything is symetrical. So fold the fabric in half before you cut and only follow that half of the chalk lines.
Now overlock the front piece to the back.
Eww, I hate the word gusset! Still, no matter what my feeling on the word are, a pair of pants still needs one. I cut mine out of the thicker jersey fabric from an old t-shirt. I just laid the half made pants down flat and traced round the middle of them to get the shape.
First pin it. Then, as always, tack it and remove the pins. Once this is done overlock round the whole thing. You'll be able to see the thread so try to use an exact colour match.
Turn the pants inside out and overlock the sides together. Trim the loose threads, and you're done!