I usually have to be up at 7AM, and I need 6 hours of sleep minimum, so I do my best to sleep at the very least at 1AM. Sadly this doesn't always work because I'm an owl and get distracted by my handhelds or tablet.
On days off I usually sleep 3AM-6AM to noon.
As for habits during sleeping... I tend to listen to podcasts while sleeping to shut down my thinking. Once I start pondering I ponder for quite a while.