Any advice on focusing on my breath?

Hey, I've been trying to focus on my breathing for a little while now and can't seem to figure it out. I'm really just looking to focus on the breath in its most natural state but I ususally end up forcing the breath and it creates tension. Any advice on on what I should i be doing mentally or physically before doing this and others ways to attain this? I'm hoping to use it to be in moment more often and to help allieveate stress to keep me going throughout the day.