assessing effacement and station

Look at diagrams of the pelvis, The spines are not located at 3 and 9 o'clock as you might think, but are more at 4 & 8.

On the posterior aspect of the vagina, you can feel the ligament that runs from the sacrum to the spines and follow it to the spines. Again, look at a good diagram of pelvic anatomy.

Practice, practice, practice. Follow the exams of your coworkers. Get to know what they consider a 0 station, or -2. If the patient has an epidural and hasn't had ruptured membranes for too long, you can do some extra exams without harm.