I typically watch my boys' behavior on a day to day basis to make sure they aren't grooming that area too frequently, having a hard time peeing...
If they are... there could be an issue and you need to hold them gently and carefully look to see if there is any redness or swelling of the penis... You can find videos on how the process works... but you need to extend the penis gently and look for any dark spots around the otherwise pink penis... once the check and/or removal is complete, you need to let it retract - using a KY lubricant can be helpful. It's a VERY delicate process (and I'm sure someone with even more detail will have an answer as well).
Otherwise, I like to leave it alone and don't poke and prod if they are acting normal.