Chubs often ends up in our bed, either for a quick feed or play, for a few hours or for the whole night. To keep her safe we have a bed rail so she can't fall out. It's just a normal toddler bed rail and it also works a treat for stopping me falling out when Chubs is making diagonal bed angels (think snow angels, but on the sheet) and there's no room for me.
We also have a waterproof cover to protect the matteress. Especially when she was a newborn, I would often leak milk on the sheets even if she wasn't in our bed, and we've also had a few nappy fails in our bed. The printed cover is just a normal cot waterproof protector, not a special cosleeping cover ot anything like that. We have three - one for her cot, one for our bed, and one spare/ in the wash. As you can see in the picture, we have a normal queen mattress cover on the mattress, then the cot mattress protector just on my side at the top, then I add sheets et cetera as normal.
Having her in bed means we all get much more sleep, which is win- win- win. Knowing that our bed is safe for Chubs is very important to me, too.