I am 40 and found that even with keeping a detailed dream journal I would still have "dry spots" - these would last 4 or 5 days and were frustrating.

I found a big help in supplements. On the supplements board I learnt about the importantce of some of the B vitamins - so I now take a bunch of those before bed. I also found through experimenting that taking a couple of L-Acetly L-Tyrosine's before bed always breaks a dry spell. I also use DMAE - a couple of these before bed I am sure has improved my recall.

Another tip is to drink alot of water before bed - When you naturally wake at the end of a REM cycle you will need to go to the bathroom - a good oppotunity to record your dreams.

Finally - I bought one of those REM Dreamer devices. Not a cheap option but I have found it to be worth the investment. It uses infra-red sensors to look for REM sleep and can then trigger lights and sound cues. It also has a dream alarm feature that wakes you during REM so you can record your dream and use DEILD methods to get lucid.