Practice slipping out of bed and not turning on the light. You might think this is a frivolous issue. It isn't if there is more than a 10 degree difference in your sleeping comfort level. It becomes a very serious issue if you like to sleep in 70 degrees and your lover likes 55 degrees. If you like a relatively warm bedroom to sleep in, check and see if your lover keeps the windows open at night, even if it is snowing outside.
Some people can sleep in the same spot all night.
Others roll around a lot. If both of you roll around a lot, there's bound to be a fight around 3 A.M. 5. Snoring is a very serious problem, especially if you can't sleep while your lover is snoring away. There are a lot of suggestions on how to stop snoring. But, short of smothering the other person, none of them work.