Water shortage? Tips and tricks

If you have some house plants or a select few plantings outside but want to conserve water, try placing a plastic bucket in your shower. The water you catch while showering would have gone down the drain anyway. Use it to do a bit of watering. If the soaps and shampoos you use in the shower don't harm you, they likely will not harm any plants either. Do you have other suggestions? Please share them here.