You may want to put a glass of water in the bathroom or on your night table the night before you wish to do the test just to remind yourself not to brush your teeth prior to spitting into the glass.
When you first wake up in the morning, before you put anything into your mouth, work up some saliva and deposit it into a clear glass filled halfway of water. After about 15 to 30 minutes, look through the side of the glass if there are any strings or deposits below the waterline.
If you do NOT have any yeast or candida concerns, your saliva should stay at the top of the glass and will eventually dissipate.
If you have candida, the test should look like the picture above. You may have all or only one of the elements shown here.