Ankle holsters work pretty well, but you do have to still watch out, especially when getting in and out of vehicles/equipment, sitting, stooping, etc. Longer, fuller cut pant legs are the better choice. Ive used one for a number of years, and with good results. You do need to pay more attention to the gun as far as dirt/dust goes, and stay on top of maintenance.
One of my favorite holsters these days, is the Smart Carry. I find its my most versatile holster, and allows carry of more realistic guns where you would normally be trying to figure out a way to carry a smaller one.
I normally wear Carhartt and Dickies "carpenter" type pants, and even with the flat, fitted fronts, the Smart Carry easily allows me to carry a Glock 26 with a 17 mag as a reload. Ive also been using a 19 in it, and with no troubles.
Its very comfortable, and of all my holsters, the cleanest holster Ive ever used. I work in a very dirty and dusty environment, and the gun and mag show very little, if any, in the way of dirt, dust, or dust bunnies. All the other methods Ive used, the guns/holsters were always filthy and required constant attention.
The biggest thing it has over the other types of holsters is, you can wear it with pretty much anything. Tucked in office/business attire is not a problem at all. You dont even need to wear a shirt or cover garment, and you can wear it in shorts or even sweatpants, as no belt is necessary.
Contrary to what it might look, getting the gun out and into action is actually pretty quick and natural, and even when sitting. The gun rides just below the belt line, and is easily accessed with one hand. It also doesnt look like youre going for a gun. More like youre tucking your shirt in. The gun sits between your shirt, and your pants, its not tucked under your shirt.