If you're somewhat motivated by moral arguments, but not prepared to go all the way, eat meat from big animals, like cows, and not small animals, like chickens. Also, if you are motivated enough, eggs are really bad.

There is an orders-of-magnitude difference between different kinds of meat, which means switching to entirely beef and dairy is almost as good as becoming a vegan. Sources: this, and this.

Also, if you are only sort-of motivated, watch some undercover factory farming videos. You should alieve in the consequences of your actions.