Many architects, designers, employees of these people and enthusiasts often find themselves in the position of needing to make photographic documents of 'designed spaces' and are often disappointed with the results. The result doesn't seem to match what you 'saw' when you were in the space. In many many cases, and with enough practice and SOME natural ability - you can make a space actually look BETTER than it looks in real life! And while I can't teach you how to be an instant Julius Shulman - I can, however, given some fairly basic equipment, indicate some great rules-of-thumb that will improve your results dramatically. Some of these are basic to photography in general and some are more specific to architectural photography.
While there is no real substitute for experience and precison equipment, it IS possible to improve on the results you're currently getting in a number of ways.
1. PUT THE FLASH AWAY AND BREAK OUT THE TRIPOD!
Use a tripod! This is one of the most important aspects of photographic image-making. Many think simply using their flash will easily remedy or obviate the need for a proper tripod - this just is not so. In fact, an on-camera flash will hardly EVER provide a quality result. Put the flash away. Using a slightly longer exposure (even if it's calculated automatically by your camera) will have the effect of evening out the ambient light sources in your project and making a 'cleaner' looking project. Pay attention to light levels however - this is especially important with regard to exterior photography (please refer to section 3 for details).
2. LEVEL YOUR CAMERA!
While this is a completely different ball of wax when it comes to professional architectural photographic equipment, as these beasts tend to have perspective correction built into their very architecture, it can be confusing and/or frustrating to get a camera perfectly level and/or aligned to a desired wall or surface when it is absolutely critical. There are some 'cheats' you can use to do this. One is to find the reflected image of your camera in a reflective surface like glass. When your camera is set up perpendicularly to the surface, all you need do is aim the center of the image at the reflection of the camera. For a vertical surface this will ensure perfectly vertical lines of any verticals in the scene.
3. BE STILL!
If your camera has any sort of provision for a 'cable release' or 'remote cord' - please use it. The less you touch the camera as it's doing it's thing, the better. That's all I have to say on the subject.
4. PAY ATTENTION TO YOUR LIGHTING
Lighting can make or break your shot! Don't be afraid to use dimmers or play with obstructing certain light sources if you feel them to be distracting in any way. For the advanced photographers, using an exposure of several seconds allows you time to have an assistant turn a light off for part of the exposure in case it's not dimmable. This is actually a preferable technique to dimming - since dimming will artificially lower the 'color-temperature' of the light (make it much warmer, or orangey-looking than it would otherwise be!).
If doing exteriors, wait for 'magic hour' - the time when exterior and interior light levels are similar - this provides a far greater sense of continuity and awareness of, the flow between interior and exterior space. Most people seem to like the effect of this. There are, of course, times and projects where this may not be such a desirable thing. But you are the best judge of what you want, of course.
5. DIGITAL OR FILM ?
While many people (usually pros) are of the opinion that film cameras (even 35mm) are still superior even to the very best consumer digital cameras, the ergonomics of a digital camera are without parallel. By ergonomics, I am referring to the 'ease of use' - and specifically the ability to review a high fidelity facsimile of your picture instantly. This could be one of the most important photographic tools you'll ever have. While there may be detail of the image you WON'T be able to see, it will give you a crude idea of what your photograph will look like. This is where one really needs to practice SEEING. You might be surprised what you might miss even on a large preview screen. While practice might not make PERFECT for a very long time... it'll certainly make better each time you pay attention to what's in front of you (this is quite probably harder than you think!).
6. ZOOM & WIDE ANGLE LENSES, DISTORTION and YOU.
Many popular digital cameras have either a built-in zoom lens or, if of the SLR-type, have a zoom kit lens. I will try to suggest how to work with these to maximum possible effect. While it IS true that many interiors can really benefit from the use of a wide-angle lens (or the widest-angle setting on your zoom), many of these have problems of their own. With wider-angle lenses, or a corresponding setting on your zoom lens, tripod use becomes critical, as perspectival effects become exaggerated compared to a 'normal' field of view, which is a little easier to control.
Before I get into the specifics of this - there is a little urban myth I'd like to clear up about something commonly referred to as 'wide angle distortion'. When people refer to this effect - what they are in FACT talking about is 'natural perspective'. A mathematical/geometric construction of the very same scene (as you could produce in popular CAD programs like AutoCAD, ArchiCAD, ReVit, etc...) will be nearly identical to what a high quality lens will give you. The simple facts of life are that objects away from the center of the image will be artificially elongated in one direction more than another. The human eye sees things EXACTLY the same way. You might try looking around the room you're reading this in with your peripheral vision and see if you don't agree with me.
The OTHER kind of distortion to be wary of (hereinafter referred to as 'the bad kind'-!) is due to using a zoom lens or a wide angle lens of poor quality. What I have to say on the subject is really only useful if you have an SLR-type camera, as opposed to an all-in-one 'point and shoot' type. Even the best zoom lenses can't be all things to all people and WILL exhibit SOME 'barrel' or 'pincushion' distortion at certain settings. This is bad. One can try to correct for it in photoshop, say, but it's just not time or cost-effective. The only real workaround is to invest in a REALLY REALLY good lens (or hire a professional, of course). A 'fixed' or 'non-zoom' lens (we call them 'prime lenses') is a good asset here.
IN CLOSING
There are quite a number of other topics I could approach, and many I still consider critical to 'the basics' but chances are you already have a headache after having read THIS far - and I don't want to give you more of one than you already have! In any event, there's no substitute for practice and feedback. And please - don't be shy to write in case there are any further questions you might have on this or other related subjects.