A.J.
I had the same problem with my son at 10 months (now 2). I would do my normal routine, then after I put him in bed I did the 5, 10, 15 minute rule. After 5 minutes go in get him to stop crying, then wait 10 minutes, and so on. First night he cried through the 5, 10, and the 15, but I didn't have to go back in after that. The next night I did the same, but the third night I didn't have to go in for the 10. Just listen for your son's tone of his cry. If it changes, go in, something else might be wrong. Start the routine over.
My son slept really well after that. If he wakes up in the middle of the night you can do the same thing. I didn't want to try this with my son, but I am so glad I did. It was taking us almost 2 hours to get him to sleep and after it took 15 minutes at most.