Here is some brief info about sleep cycles and recall. First of all, we tend to naturally wake after the end of each cycle, which finishes with REM. Some people are aware of these moments, while others are not. In the beginning of the night we experience more N-REM phases and REM sleep is shorter, we sleep deeper, so it may be hard to become aware of those micro-awakenings. As the night progresses and we become well rested, REM cycles become longer and our natural wakes might be more noticeable. Also, while there is a tendency to state that each sleep cycle lasts 90 mins, the truth is this is an average and they can vary between 70 and 120 mins, therefore it can be hard to exactly pinpoint the time where one cycle ends and the other one begins.

The implications of this for wbtb:

- with wbtb you usually will set the alarm or use a natural wake after 4-6 hrs of sleep or something like that depending on your sleep schedule, the amount of time you have available, etc. This means that REM cycles will already be somewhat longer, so there is a greater chance that your alarm might hit during REM (in case you want to have some pre wbtb recall) and it will be easier for your to use natural wakes for wbtb and recall.

2) Yes, it will be better if you keep your baseworld consistent and don't change many elements. When you repeat the same process/though over and over, it will be committed better to memory than if you alter things. But you can have a portfolio of baseworlds, dreamscenes, etc. You can later use elements of these portolios or the entire portfolios to shape your dreams (i.e. summon items, change the scene). You can also try to use them as dream signs, if you associate them with the realization or feeling of lucidity.

Good luck!