After struggling with this same problem for some time, my conclusion is to make or have made an IWB holster which positions the grip just above the top of the beltline as with Mexican carry. The grip is easily covered then by blousing out your shirt over it. So far, I have found only one holster on the market that carries the gun in this manner, by Bulman Gunleather for $122. Kinda steep for an IBW, which need not be fancy. Most IWB's seem to position the gun too high to effectively cover with a shirt, especially if you move a round a lot. The DeSantis Insider @$25 puts the grip too low in relation to the belt and slows the draw, although it might be easily modified to ride a little higher. The Insider will get you going cheaply, however. I rule out any further IWB with an infernal metal clip. Too hard to get on and off. The most promising tuckable IWB I have found by far is by El Paso Saddlery, which uses snap loops in lieu of a clip. It's a pretty sure thing that a tuckable will conceal 100 per cent of the time, keeping you in compliance. I'm not sure about draw interference, however.