Forgot to bring your tripod and desperately want to use your non-image stabilized tele without camera-shake? Use the "over-the-shoulder" technique!

Support the long lens on your left shoulder (this is easier for lefties (left eye dominant)) and aim it backwards. Yes, it seems like looking over your shoulder, but this way you provide a solid base for your lens. Don't drink too much or rest your hip against a wall.

I only clean my DSLR sensor when I am at home. Sometimes, when I'm on a long trip and I change lenses very often and there can be some irritating sensor spots on my photos.

At home, it takes some time to find all the sensor spots and "heal" them. Sometimes I don't see one and I have to adjust it later. My tip:

At the END of your journey (the moment you have collected the maximum amount of dust on your sensor), shoot one photo of the sky with a small diaphragm (F10 or smaller). At home, import that photo, increase contrast and you will be able to view the senors spots easier. Copy this layer onto your images to examine the spots. You can make circles around the spots in a separate layer with a smashing color to detect them even quicker.

Or, buy a camera with sensor cleaning functionality....