Many things get natural with extensive shooting.  My mother used to wonder why I would just sit and click a shutter, or play with the camera.  It looked like just boredum relief to her, but in later years when I had to depend on a camera for my living, it became important to know how a shutter should sound when it's working properly, and the operation of the camera needed to be second nature.  Even with modern digital you need to know how fast it responds, when to over ride the automatic system and such.

I learned on totally manual cameras back in the fifties.  I still enjoy getting out the classics and shooting, but when I have to produce, I pick up the modern equipment.  Autofocus, auto exposure, auto flash, auto film handling - all contribute to reducing the chances of error.  You still need to check out your equipment if you have time.  I will be doing some shooting for our church directory soon.  I plan to use a flash I haven't tested yet.  Before I do that, I will go out with the camera, lens and flash combination I plan to use and shoot a 12 exposure roll of film for evaluation.  Not much, but it will verify the camera and flash are working in dedication to each other, that the flash is putting out the amount of light it is rated at and that the camera is functioning properly. 

Most serious amateurs and professionals have the shutter release over halfway down before anything happens so it is just that last small motion to shoot.  Some of that requires a bit of use of your camera so you get a feel of how far you can push without it firing on you.  And, there will always be surprise shots where you have no choice but to fire fast. Even then, the serious photographer rarely jabs - they usually have a grip on the camera that allows fast release of the shutter without jarring the camera.  A photo class teacher I know has students go out and shoot something with definite pattern, like a brick wall, and try different speeds to see how slow they can handhold without noticable loss of detail.

Most people that do a lot of shooting discover that a 35mm SLR works at least as efficiently if not better in the vertical position.  Hold the camera as shown with only either hand.  Then try it with only one hand in horizontal.  You should have a better, steadier grip on the camera in vertical.  Plus, the vertical image is more dramatic than horizontal.  Some things need to be shot in horizontal, but get out of the horizontal syndrome and turn the camera.  You will find your photos more effective when you show them off.

This is tough for the occassional shooter.  Serious photographers that are still using the old style cameras generally know their camera is set for correct exposure at any given moment, or if they have to grab the camera can guess a reasonably close setting and set it and shoot.  The old rule of thumb was in an emergency, shoot, then check your setting, and if there is another chance then adjust the setting and shoot again.  Modern auto exposure, autofocus cameras reduce this problem significantly, but be careful about getting overconfident and accidentally leaving it in a wrong mode.

It seems easy enough - push the button, match the reading to the dial and read out your exposure.  I think modern Slicon meters have reduced a problem that was common on Cds meters -  I found my old Gossen Luna Pro would give me underexposure indoors.  I have heard that possibly Cds had higher red sensitivity than film, resulting in readings that didn't match the film under red, ie tungsten, light sources.  I find even modern cameras will often underexpose slightly indoors though.  If you have this problem, set your exposure compensation to plus 1 stop, or cut your ISO setting in half (ie, if using ISO 400, reset to ISO 200) when shooting indoors.  Don't forget to switch it back though when you go outside.

Back in 1959 I thought I really was uptown when the high school added a Metz 103, like the flash on the left, to yearbook shooting equipment.  One piece units were just starting to be available and this was very modern at the time.  Today I don't have the latest in dedicated flashes, but the Vivitar 5600 on the right is a very powerful flash with limited dedication.  It has bounce and swivel.  I recommend using bounce/swivel with caution.  Most pictures look better with the contrast of direct flash instead of the softness of bounce, but both have their applications.  A good compromise is a bounce card, that give less intense shadows while still giving some direction to the light.

In almost any situation you can produce sharper pictures by shooting using a tripod.  It is obvious that you need it when using slow shutter speeds, but it helps even outdoors.  That being said, I have to admit I am too lazy to carry a tripod around and so most of my outdoor shooting is hand held, just like the rest of us usually do. I do keep a tripod in the car regularly, and it does get used occassionally, and it does make a difference.