Mix in with a pin and then put onto a warm surface such as a hot plate. As the water evaporates make scratch marks with the pin. This will cause crystal growth to go in lines, you can alter the growth by breathing on the slide. I hope that you feel inspired enough to try your hand at making some slides. There are all sorts of other subjects that can be tried.
Epsom salts is good for crystal slides, as is aspirin.
Some plants have small scales on the leaves and I hope to make some slides of these soon. As soon as I get my hands on some sea-buckthorn leaves that is. All images taken by Mike Samworth . Please take the time to ask any questions or make any comments to me Mike Samworth . Two articles describing how to obtain and use polarised light filters are 'Technicolour Nature' - Lighting techniques for the novice Part 1 and Part 2 .