A plate should contain colored vegetables and/or meat, deliciously arranged and dressed in sauce.
A plate should open your appetite as much as it will cover your gastronomic senses.
I am not a very traditional cook. I search for interesting recipes in certain books, I watch TV shows, or I "steal" recipes from restaurants by tasting and guessing the ingredients.
But what I love most is to share all those with my friends and to photograph the steps of each new recipe.
If you wish to photograph food and you don't have all the necessary equipment, it's better to think first at the available ambient light. If lucky, choose the natural light coming from 1 source (a window let's say). It will increase the contrast, the luminosity of the colors and it will make the plate more attractive to the eyes.
Be careful to choose the correct white balance from the beginning. I use the custom settings or judging by the light source I choose directly the color temperature (in K degrees).
Make sure to choose the best part of the plate, the better looking I mean. Choose a good angle in order to show the size, the form, the ingredients. You can photograph from above, perpendicular, when you want to show texture, or from above at different degrees when you want to show the forms and details.
If you don't have some natural light available but you have an external flash, bounce the light into the walls of your kitchen or even into the cap of the gas stove (if it's white). Use the interior light of the oven when you wish to create exactly the mood. You will probably need to increase the ISo, but make sure you will keep it at no more than 400. Depending on the camera, increasing the ISO might make noise appear in the image.
When one (or more) cooler source of light is available instead of natural or flash light, my suggestion is to change the white balance. Also to move the plate (if the source of light is fixed and coming from above, perpendicularly) until you find an angle that will provide a game of lights and shadows. That will make the dish present all forms and levels.
Using instruments - a spoon, a fork, a knife - will bring a plus to your composition.
Use herbs. A touch of oregano or parsely will give contrast and elegance to your plate.
And more than anything, use your imagination. You can create while cooking and cook while creating.