Drawing a pistol in detail:
Step 1: Go for your gun and un-clip the holster. If you got a hip holster under a shirt, lift up the shirt.
Step 2: After pulling out the gun, quickly rotate it so that it's pointed at your target. Can you start shooting at this point? Yes, if your target is pretty close.
Step 3: Bring your other hand to support the gun, while keeping it tight to your chest (in the case that some asshole tries to grab your gun) Can you start shooting here too? Yep.
Step 4: Extending your arms in a punching motion (known as 'punching out' your gun) Now you can aim properly.
Edit: chest holster added