I do all of these things. As you've all said there's usually at least a week's worth of product left in the tube and I too hate waste.
I'm almost ashamed to admit this but I also use a teabag twice, but only for myself!
Here another money saver. If you have grubby patches on your carpet in front of chairs etc, instead of buying expensive carpet cleaner which doesn't work, sprinkle on some bicarbonate of soda, brush in with an old toothbrush, leave for half an hour and vacuum. Much better results. Bicarbonate is great for lots of cleaning jobs actually. Internet is full of them.