I hate tuckables.
I'm standing there in my shorts, with my pants hanging around my thighs, trying to hold my holster positioned properly on my belt while getting my shirt to drape naturally over the grip of the gun, while neither the gun nor the belt nor the shirt will stay in place until I have the pants buttoned and zipped and the belt buckled.
No thanks.
Give up on the tuckable IWB.
Get any IWB holster you like. Remove all the fastening tabs, loops, whatever. (I used a FIST K1).
Go to the hardware store and get some stick-on velcro. Peel the backing paper off one half and stick it to the outside of the holster.
Go to a clothing store and buy a stretch web belt. Then stop buy the fabric store and buy some sew-on velcro. Sew one half on the inside of the belt where you want to hold the gun.
Put on your shorts. Put on your new belt. Place your holstered gun inside the belt so the velcro meshes.
Put on your shirt. Put on your pants. Put your old belt through the loops, and buckle up.
A tuckable IWB carry, that's easy to put on, drapes more cleanly than you can manage stuffing a shirt-tail intol that little slot in a tuckable holster, that stays on when you drop your pants in a public toilet, etc.
Or you can use the same gear as a deep carry. Put the stretch belt on over the top of your shirt-tail, but lower on your hips, placing the holstered gun so it's entirely covered by your pants.
I do this, usually. At about 2:30. With the butt of the gun just behind the belt of my trousers.
I find it faster to push the holster up above the belt-line than to pull my tucked shirt-tail out of the way. I can, and have, pushed it up to IWB carry in situations where I thought something untoward might be pending.
I take of and put on the gun by removing and replacing the entire holster. I take the holstered gun out of the cabinet at home, put it on my belt, take it off my belt to put in into the safe in the car, etc., without ever holstering the gun - which eliminates any possibility of something, perhaps my shirt tail, from snagging the trigger.
And the motion of putting on and taking off the gun is simple, fast, and unobtrusive. I've done it in parking lots without attracting attention.
And for winter, I just sewed some velcro on the inside of a pocket of my winter coat. Drawing from a belt holster from under a heavy winter coat is impossible - pocket carry is much better.
And again, the movement is fast, easy, and not attention-getting.
I got the idea from Andy Arratoonian's "TJM Holster":
http://www.holsters.org/deepconceal-holster.htm
I don't actually use his holster, but it's from him I got the idea.