There are a few ways and sometimes you have to mix it up during a swim. If you can you should trickle breathe a small amount as soon as your head goes into the water then just before you turn to take a breathe give a short sharp burst to exhale all that’s left . This allows your lungs to act as buoyancy for as long as possible.
If you’re struggling try breathing every other stoke. Make it as natural as possible. Relaxed. And don’t kick too much! It’ll waste all your energy only kick to keep your balance.