Getting a new pair of boots is always fun. You've probably been sitting on your phone surfing through cleat after cleat for days until you finally found a pair that would match your unique personality. That being said, we sometimes don't end up getting a pair of cleats that would work best, just a pair of cleats that we thought would look the coolest.
Most of the newer/higher-end cleats are engineered in such a way that “breaking them in” is no longer an issue. The fabrics and materials used mold better and faster than older materials. All-leather cleats are awesome and hold up well, however, they have a downside. Leather needs time do be worn in and mold to your foot. This is why you may have heard crazy stories about people wearing their cleats in the shower or putting their cleats in the oven.
After many years of experiences and wearing more cleats than I can keep track of; I have found several tricks to the trade. When you get a new pair of cleats, be smart and wear an extra pair of socks to protect your feet from blistering. Getting just one blister will cause sometimes weeks of misery and discomfort.
Don't go sticking your cleats in boiling water or cracking eggs on them. Just play the game and feel for hot spots that seem to be bothersome and be sure to bandage up those spots.
Remember that getting new cleats is supposed to be fun and if you don't take care of your cleats and feet, it won't end up being much fun.