How to make sleeping on bunk bed more comfortable?

As stated, a mattress topper will help, but your favorite pillow will also help.

Bed wedge for your head and legs.

A body pillow to snuggle against.

Soft, fluffy comforter.

An air purifier in the room. An additional fan

A massage when you get up in the morning. (oh sure, it's not likely, but it does help.)

Get a good mattress or an "egg crate" foam mattress cover.

Buying a decent mattress is always a good idea.

What other part of sleeping in a bunk bed do you find uncomfortable?

A mattress topper can make a big difference in the hardness .

Sleep in the bottom bunk unless who's in the top bunk is a bed wetter. Why? Because it's always too hot in the top bunk near the ceiling because heat rises and it's a good five to 10 degrees warmer in the top bunk. Otherwise, the comfort between a bunk bed and just a regular twin bed are the same because a bunk bed is just two twin beds stacked.