Shortly after arriving on Deep Space 9, Benjamin and Jake Sisko went to their quarters and found there were no beds. Chief Miles O'Brien told the two that a spare bunk was available from the Enterprise-D. (DS9: "Emissary")
Cardassian beds were also found to be uncomfortable to Humans, but according to Vash, sleeping in any bed, even a Cardassian one was a luxury to her, since she usually slept on the ground in tents. (DS9: "Past Tense, Part I", "Q-Less")
As Odo was a shape-shifter he did not used a bed, though he had liked sleeping in one when experiencing humanoid life. While sleeping, he would lose his solid state and turn to a gelatinous substance, causing him to slide onto the floor. (DS9: "In Purgatory's Shadow")
Beds were mostly used for getting rest, either by lying quietly or sleep.
In 2266, Dr. Leonard McCoy ordered geological technician Fisher to bed. (TOS: "The Enemy Within") In 2364, Dr. Beverly Crusher ordered Captain Jean-Luc Picard to bed after he contracted a virus brought to the USS Enterprise-D from Quazulu VIII. (TNG: "Angel One")