Ideas to spice up the bedroom

Me and my bf mostly only do missionary and for one it doesn’t last as long as I would like it to. Maybe 20 min at the most. I’m sure he can last longer but he just gets tired bc of his work schedule. And sometime when we haven’t seen each other in a while or if he’s drunk we’ll do a few other positions like from the side, my legs on his shoulders, or cowgirl. I kind of want more tho. But idk what to try. It won’t work talking to him about it, I think it’ll just be best for me to take initiative but I usually go blank when it’s time to do that. Like I just don’t know what to do at the time.

Does anyone have some ideas/advice