One useful thing I learned in professional development this summer was the 10-24-7 rule. The rule says that in order to get information to go from short term memory to long term memory, a new concept must be practiced within 10 minutes of learning, again within 24 hours and then again within 7 days. I have tried my best to put this into practice this year. I made several posters for my room illustrating the 10-24-7 rule, not only to remind me, but when students start to complain about homework or warm-up problems, I point out the posters and tell them I'm just trying to help them process the information from their short term memory to the long term memory.
This is not a novel concept, but students must practice something on their own or summarize the concept in words or pictures within ten minutes of learning. There are so many strategies to accomplish this. It might be a homework assignment, it might be cooperative learning, it might be a quick write, or simply having a student summarize verbally what was learned. For the 24 hours, I try to do a warm-up (Do Now, Bell Ringer) every day to practice the concept learned the previous day. For the seven days, I try to include review problems on my assignments that cover material learned the previous week. For some reason, students don't take these problems seriously. I think in their brain, they say, oh this is just a review problem, I'm going to leave it blank, or just guess (since a lot of them are multiple choice TAKS type problems). The way I've solve this is I now include these review problems on unit tests. I keep telling the kids not to skip the review problems because they'll see them again on the unit test. Some take me seriously and some still haven't gotten the message.
With all the distractions a teenagers faces it is sometimes a miracle they learn anything, but for me, the 10-24-7 rule has been a very effective way to help my students retain information. Try it, you'll like it!