I know it is not safe when viewing a solar eclipse to look directly at the sun. I know you can purchase solar eclipse glasses online but how do you make your own solar eclipse glasses that are safe to use for solar eclipse viewing (and let us throw in the transit of Venus)?
Making your own eyewear for direct viewing of the sun is probably not too practical. You essentially need a filter that blocks well over 99% of the incoming light. You can use #14 or #16 welder's goggles for this, or obtain specialized filters designed for this purpose. These filters are a glass substrate with a metal deposition layer on them that is designed to transmit only a small fraction of the light.
As an alternative to direct viewing, it is much easier to make a system for projection viewing of the sun. In this case, you would create a projected image of the sun on a surface, and observe the image. You can look up "solar pinhole viewer" or check out these instructions for details on how to put together a simple solar viewing system with stuff you may have around the house (cardboard, paper and aluminum foil): http://www.exploratorium.edu/eclipse/how.html
For more on observing the sun, see this article: http://www.skyandtelescope.com/observing/objects/sun/Viewing_the_Sun_Safely.html
I don't think I would recommend any of the traditional ways of making them - it's too easy to make a mistake and hurt your eyes.
The best way to view an eclipse is with a pinhole camera use telescopes/binoculars to project the image onto a wall.
If you want to look at it directly a piece of welding glass (the screen from a welding mask) is probably the cheapest easiest safest way - you should be able to get it from a car parts / machine store.
edit - just for the lawyers: Welding glass for electric arc welders strongly blocks UV, the wavelengths you have to worry about. Older gas welding masks might not have good UV blocking.
If you have a camera on your phone point it at the sun and look at the screen. any camera with a screen will do. this way you can take pictures too