Glock 42 in a concealment express holster. I carry this for the summer mostly. This combo is practically invisible with even just light shorts/tshirt.
Other times I’ll go with a Taurus pt111 also in a concealment express holster. Not quite as easy to conceal as the g42 but hides surprisingly well in summer attire. Very happy with the concealment express IWB holsters.
Source:: Concealed Nation