The time you are more likely to remember a dream is right after waking up from it. Especially if you have a tendency to wake up during the night, you can use this to your advantage. This is the reason it's a good idea to keep pen and paper near your bed. But, just how to make use of taking nightly notes depends on your sleeping habits. I've divided this into light sleepers and heavy sleepers.
However, everybody will need to keep pen and paper at your bedside. It's not necessary to turn on the light when you take dream notes, as long as you can decipher your writing. You can use a tape recorder as an alternative, as long as you don't have a bed partner or roommate.
Use of nightly notes for sleepers who awaken during the night
Build up the habit to have your first thought when waking up being this: "What was I just dreaming?" Whenever you wake up and remember something, write it down. If writing down a full dream in the middle of the night wakes you up too much, then just write down some keywords to help your memory. It's better than nothing!
Use of nightly notes for heavy sleepers
If you're not used to it, it can seem hard to wake up in the middle of the night. However, it's not impossible! If you sleep alone, you can set your alarm clock to wake you up at approximately 90 minutes intervals, or the at time of night of your choice when you think you will be in REM sleep. This can be combined with WBTB. When you wake up, focus on remembering your dream(s) and write down at least some keywords to help your dream recall. If you can't use an alarm clock, you can drink plenty of water before bedtime, and let nature wake you up during the night.