I typically wear an untucked tshirt with an unbuttoned and untucked denim shirt over my IWB holster. I know that's 2 layers to move to get to my gun but provides the best concealment for me. I'm 6'2 280lbs so concealment presents it's challenges. I have noticed, like you, that a patterned shirt helps hide any printing, particularly a darker shirt. I have a button down that is a Hawaiian print but is black and white so it works well. Even plain colored dark shirts are better than light ones. You just have to play with your wardrobe and see what works for you. I've only been carrying for 3 weeks so I'm still figuring this out. Good luck!