The most important tip in producing high quality portrait images is to know how to get the most from your subject. The least important item in portrait photography is worrying about what camera gear you have or require. There is no point having amazing photographic gear (where it be high end digital DSLR like a Canon 5D Mark II, a classic Leica camera with the incredible Carl Zeiss lenses or a professional medium format camera such as a Hasselblad if you cant engage with and get the most from your subject.
I got talking to this interesting character in Dalat, Vietnam. He initially made a very half hearted attempt to see if i needed a taxi ride for money. After politely declining, I expected him to either leave to find more business or to barter me down for a cheaper ride. Instead we got into a half hour conversation about my home town of Perth, Western Australia and how different it was to his, the beautiful mountainous city of Dalat in the south of Vietam.
We chatted and chatted and he talked about how his uncle or cousin...not sure which due to the difficulty understanding each other, had moved out to Australia and how life was for each of us. He eventually asked if i could take his picture. He was initially quiet stiff and the first photos reflected this. After a few shots he began to relax a little and started a new cigarette. This portrait really does something for me. Through Adobe Photoshop CS5 i have given the image a retro, warm feel with slightly distorted colour balance. I have made a couple of pre-set actions to enable me to process these type of images quickly. I can't recommend Photoshop actions enough especially if you have a lot of images to process that are of similar exposure and tone. You will run into trouble if your raw images differ dramatically with ratio of highlights to low lights. I normally try to avoid batch processing unless my lighting conditions are identical from shot to shot.
In terms of getting the most from your portrait photography other suggestions i have is to play and experiment on friends and family so you get a feel for what works when you get to a commercial photography shoot or using a real model. Experiment with different lighting effects. Personally i like using natural light far more than artificial lighting such as on Camera flashes or soft boxes in a photography studio. I love the effects that can be achieved with natural light from the sun streaming in from windows and doors. Stunning results can be achieved by simply placing your subject near a window and using a reflector of any type (i like to keep a collection of scrap white cardboard and polystyrene foam) to use to reflect light back onto the shadow side of the face.
The second tip i like to recommend for interesting portrait photography is to experiment with perspective. Try to find an unusual perspective that is different from standing eye to eye with your subject and shooting. Getting down low and shooting up or getting up on a chair or step ladder and shooting down can often provide a more dynamic photograph. If I'm out on location, it wouldn't be unusual to find me lying in dirt or climbing on top of bins, benches to try and find a point of difference to make an interesting photograph.
Thirdly, don't be afraid to get close to your subject and fill the frame. Alternatively if the subject is in an environment that helps to tell a story, don't be afraid to show this as well. A portrait can include its surrounding environment, especially if it helps describe the character or add something to the photograph and subject. I often try to include the subjects environment if I'm taking travel portraits or if the place is critical to explain a story behind the subject.
So to summarise. Get out there today and start shooting…Nothing will give you better photos than playing and experimenting with different situations and conditions. You don't need a fancy professional camera or photographic studio with light boxes and continuous backgrounds just a willing subject and a belief in your ability to get the best out of them.