The following are some very comprehensive instructions for making your own Irish whistles and Didges. The only difficulty may be trying to find the right materials in your own country.
Irish Whistles
PVC Whistle
Get the sweet sound of the Irish whistle with just some... electrical conduit?? Yes, you can make your own set with some PVC pipe, and with great results! The whistles this guy makes retail for 28 to 75 USD - but only because people asked for them. He gives a very detailed step-by-step guide on making your own whistles with measurements and all! His whistle was even given some good reviews by an online reviewer!
How to make the 'Low-Tech' Whistle guide: http://guido.gonzato.googlepages.com/whistle.html
Listen to the 'Low-Tech' Whistle here!
Read the reviews at http://www.tinwhistler.com/index.aspx. Under "Whistle Reviews", click the High-End pull down menu and look for "Guido Gonzato 'Low-Tech' Whistle".
Copper Whistle
Here's another detailed guide on making an Irish whistle, this time in copper! I couldn't find the copper tubing with the right diameter so I bought me some aluminium tube instead. Maybe it'll work just as well...
Here's the tutorial: http://www.geocities.com/SoHo/Lofts/6611/makewhis.htm
Didgeridoo
PVC Didges
Now that you've looked at PVC and copper tin whistles (ha... the irony... Methinks Irish whistles shouldn't be referred to as 'tin whistles' if made in other materials), we'll take a look at other stuff you can do with PVC pipe. For this one, you need larger pipe - the type used for water - and a few different materials. This tutorial also steps you through the making of your own didge, this time with photos!
Making PVC Didgeridoos guide: http://www.geocities.com/gangwise/didgeridoo
If you're concerned about the tuning of your didge, check out this chart!
Cardboard Roll Didges
You can make didges out of cardboard rolls too (the long ones used to roll fabrics). I tried making one but haven't finished painting it.
Unlike PVC didges, bending it to shape or making a bell isn't as straightforward. One tutorial stated that you can put a bottle into one end and spray a bit of water over several days to get the cardboard to expand in order to make a bell. I'm a little skeptical, but you can try it. Just be careful your didge doesn't grow mold.
The steps are just as straightforward. You just saw the didge down to the right length (and pitch) and fix a mouthpiece (beeswax or otherwise) then paint it with acrylics. You can spray lacquer over it and use shellac to waterproof the inside somewhat, but I haven't tried it out. I'll post the photos another time.
"If you can't afford a good genuine Didgeridoo, one of the next best things in sound quality is a plastic pipe - and its certainly the cheapest option. There is one source for a Didgeridoo, which can be even cheaper and that is the cardboard rolls used by fabric merchants to roll the material on. You can probably pick those up for free at fabric retailers. It's advisable to give them a coat of varnish or wood glue to harden them and improve the sound of the didgeridoo."- Excerpt from http://www.didjshop.com/shop1/make_your_own_didgeridoo.html