I know you've seen 'em hiding in the back of the studio; those colorful blocks, long straps and cushions. But what are they for? First of all, props are your friends. They are there to support you and your practice. Your yoga practice should be as unique to you as your body and soul is to the universe. There isn't a one-size-fits-all yoga practice. We all have different body types that come with a history of injuries, sensitivities, structure and so on. So, to expect every yoga pose to look exactly like the person next to you is kinda ludicrous! Like I was saying, props are there to support you (and prevent injury).
Here are a few options to get you started:
Blocks
Have 3 different heights for support as you gain mobility
Help you reach the floor without compromising alignment
Great to sit on in order to get the hips above the knees to promote a long spine
Act as a footrest below your desk to improve posture while sitting
Straps
Helps you reach (especially when clasping hands behind your back)
Allows you to practice a posture when you otherwise may not be able to reach (dancer pose)
Bolsters/Cushions:
Great for relaxation (under the knees) to prevent strain in lower back
Lifts hips above knees when seated (easy pose)
Blankets
Creates cushion beneath sensitive knees when in table top (lay it across the center of your yoga mat but leave room at the front and back)
Warms you up during relaxation
Another option to lift the hips when seated
This is by no means a complete list, just a great place to start. If you love using props in your practice, what's your favorite part? If you don't use props, let me know why in the comments below!