Short answer, from a shooting instructor -- "practicing" bad habits is never a good thing.
If you aren't hitting well, there is a reason for it. Find the reason, address the problem, solve it, and ingrain GOOD habits that will prevent days like this in the future.
Long version: Statistically, most folks don't miss the target because of stance, grip, breath control, shaking, or even sight alignment problems. They miss because of one thing -- poor trigger control. Slapping/jerking the trigger causes a host of problems, most obviously that the excess pressure on the trigger causes the gun to move a tiny bit at the last possible moment, disturbing the sight alignment. You don't usually notice this last-second movement, as the gun bounces in recoil a split-second later, obscuring the problem. If you've ever seen the front sight dip downward just before firing, or if you've ever pulled the trigger on an (unexpectedly) empty gun, and the front sight dipped or moved off to one side -- those are signs of trigger control problems.
Trigger control problem diagnosis and correction: When shooting, if you KNOW the exact moment the gun is going to fire, you aren't squeezing the trigger, you're pulling/jerking/slapping it. When shooting, don't think "Ready, set, Fire!", think "Squeeeeeeze until it fires, watching the sights all the way through the squeeze." Add a little more pressure, a little more, a little more, until "Bang!", the gun fires and surprises you. Yes, I know the sights are moving around on the target as you squeeze; it happens to all of us. Hold them as close to center as possible, and squeeze gently until the weapon fires. If you do that, you will have good hits on target. If you rush the trigger squeeze, jerking or slapping the trigger as the sights swing across center, you WILL miss. THIS IS THE MOST CHALLENGING PART OF SHOOTING A HANDGUN. Especially once you have ingrained bad trigger habits, it is VERY difficult to get back to squeezing properly.
Sometimes, I train folks who are missing the target a lot and can't make the connection between the importance of trigger control and good shooting. To get the point through to them, I have them just hold the handgun on-target, keeping the sights as close to center as possible. Then, as they hold the gun, I squeeze the trigger for them, and when the shot is fired, the hole appears near the center of the target (Warning! Two people running the same gun is tricky, and done improperly, can be dangerous -- do not attempt!). The point of this drill is, they are doing everything (stance, grip, sight alignment, breath control) EXCEPT pressing the trigger, and when I do it correctly for them, they get good hits. This demonstrates exactly where the problem lies, and once I give them the tools and direction to fix it, and they usually improve quickly.
Once you are getting good centered hits, you can gradually speed-up the process, BUT IT DOES NOT CHANGE! The speed at which you execute the trigger press/squeeze does not change the character of the motion; gentle, controlled squeeze/press, straight to the rear, so you don't mess-up the sight alignment. Famous instructor Jeff Cooper called it the "compressed surprise break"; you compress (reduce) the time it takes to squeeze/press the trigger, but it still surprises you when the gun finally fires. This surprise also takes care of anticipating the recoil; if you know the gun is about to fire (because you're pulling/jerking), you will involuntarily push into the gun, trying to "beat" the recoil, and usually push the gun off-target. If you are not exactly sure when it will fire, you CAN'T push the gun off-target prior to the shot. You may well jump in surprise AFTER the gun fires, but that's okay; by the time you jump in REACTION to the noise/recoil, the bullet is already in the target. You'll quickly get used to the surprise release, and then you can work on shooting more quickly, but still with good control and solid center hits.
"Placement is power" -- seen in an article by Stephen A. Camp
(RIP, Mr. Camp; you will be remembered, and missed)