When I first started photography, I didn't give much thought to cleaning, let alone maintaining the equipment. But I realised soon enough, when I got my first smudge on the front element of my lens, cleaning and by extension, maintaining your equipment is important.
Lenses are probably the most expensive part about photography, and proper cleaning technique can help avoid costly repairs or servicing.
I started out cleaning finger prints and smudges on lens elements with a technique taught to me by a friend of mine. The technique involves breathing on the lens element to fog it up and then using facial tissues to wipe off the condensation. Although simple, it works amazingly well. It is also one of the cheapest options, although you do go through quite a number of tissues if your lenses are dirty.
These days, I use a number of methods in combination. I also use micro-fiber cloths to clean my lenses, but I make sure to wash the cloth often so you don't end up scratching your lens with dust embedded in the cloth. Recently I gave the LensPen a try, and I find it to be very effective at removing fingerprints. Way more useful with stubborn smudges than either tissues or micro-fiber cloths.
Things to keep in mind:
Don't apply too much pressure on the lens when wiping to avoid scratching it with small dust particles.
- When using a blower on the rear lens element, don't blow directly on the lens itself as most lenses aren't sealed at the rear, you risk puffing bits of dust right into the barrel of the lens. Instead, carefully aim the nozzle of the blower at a 30-45 degree angle.
- If using a brush to brush off dust, make sure you use a blower to clean off excess dust from both the lens element and the brush itself before starting.
The lens barrel is way easier to maintain and clean than the lens element. Most of the time, all that's needed is a brush to brush off the dust. Sometimes, you may need a damp cloth to wipe off sweat, but be careful and gentle when wiping.
The lens mount and the contacts on the mount that lets the camera talk to the lens require less attention than a lens element. In fact, I'd stay away from wiping the contacts directly, although I do keep the lens mount itself clean by wiping it with a cloth or facial tissue every once in a while.
Bodies are like lens barrels, there really isn't any real delicate area to worry about if you're cleaning externally. Much of the same applies, a brush and if necessary a damp cloth. However, if you are going to use a damp cloth, I recommend removing the battery first.
DO NOT EVEN ATTEMPT TO CLEAN THE SENSOR YOURSELF. There, you've been warned. Sensors are notoriously sensitive. I recommend that you send it to a camera technician to get it cleaned. The only thing I've done with my sensor is to carefully blow on it using a blower. If you can't dislodge that speck of dust that's annoying you, no amount of blowing is going to get it off. Send it in.
The mirror in a DSLR is even less hardy than a lens element, so, DON'T TOUCH IT. Blow on it if you must, but that little bit of dust isn't going to affect the final image. If the mirror is *really* dirty, it may affect your focusing. In the 4 years of my D70s' life, I've never had to lay a finger on the mirror, and you shouldn't either.
Bag and storage box / dry box
Most people forget these two... no point keeping your camera and lenses clean if your bag and dry box is full of dust. 😉
I haven't covered flashes, tripods and so on, but I think for these items, general cleaning practice applies.
*** Oh, and lastly, I take no responsibility over your actions. What works for me may not necessarily work for you. So, don't blame me if you scratched your lens by accident!