Use one that is water-based, not vaseline. Lean back against a pile of pillows on a bed or couch. Let your knees fall out to the sides and relax. To insert the speculum, hold it in one hand, handle up, bills together. Use your other hand to open your labia, or lips of your vagina.
Some women prefer to insert the speculum sideways, and then turn the handle up.
Go slow, and stop to relax if it is uncomfortable. Slide the speculum in as far as it will comfortably go, squeeze the handles together. This opens the bills, stretches the vaginal walls and allows you to see your cervix. Hold the handles together, and slide the short handle down and the long handle up. When you hear a click, the speculum is locked open.