It's something I've been working on over the years. Women are warm and wonderful to touch, and no moment spent with one in my arms should ever be considered wasted. The female form is the one true art, and appreciating their breasts is one of life's true pleasures. Yes, I'm programmed to do so - but they're people first, and ogling is rude and demeaning. So as hard as it can be sometimes, don't.
If a man wants to appreciate breasts, I recommend being a good person and treating women well. With luck, someone who has them will take a liking to you and let you appreciate theirs. But guys, they are theirs, not yours.
Maybe growing up with militant feminist parents had an effect.