but you can use a 3x5 card, which is cut to a 3x3 card, which is smaller than the B8 10 ring and will give you more a challenge. You can also download a B8 replacement center (find the B8 target) and print it on a standard white paper if you choose to do that. 
25 yards
NRA B8 Target or 3x5 card (3x3 card if you are feeling confident/cheap)
10 rounds, two hand standing free style, not timed
score
10 rounds, two hand standing free style, 25 seconds
score
10 rounds, two hand standing free style, 10 seconds
score.
Explanation:
Once you have your target setup, load three mags with ten rounds, get on the 25 yard line, with one magazine loaded, other two on you. Then you make sure you get your natural point of aim, Bill Rapier explains this well and you should do exactly what he says to find it.
Once you get your natural point of aim, for the first ten rounds you should not have a time limit. Every single shot should be as perfect as you can make it and that means follow through, one shot equals two sight pictures. For slow aimed precision shooting with a pistol, I do trigger reset which is a carry over from bulls-eye shooting. Ten rounds, no time limit, trigger reset, focus on the front sight. Tuhon Tom Kier explained that you should try not to leave your arms hanging out there for longer than four seconds, if they are out there longer than that it may affect your accuracy due to fatigue, retract them, relax, breathe in through your nose, hold the breath and present your pistol out, focus on the front sight and fire within four seconds. Do this for all ten rounds, make you get two sight pictures for every one shot. Once your gun goes empty perform a reload with another ten round magazine, do your scans and slowly reholster. Go to the target and score/mark it.
If you do not want to use three different B8 targets, you can use just one, just mark the impacts with tick marks, one for the first mag, two for the second mag, three for the third mag. The above B8 replacement center was for a 200 drill, keep the red lines in mind, I will explain them further down.
After you mark your ten rounds, get a shot timer, or just use your phone to count down. Go back to 25 yards, find your natural point of aim, set your count down for 25 seconds or activate your shot timer, and shoot all ten rounds in 25 seconds. Once you do this, reload with your last magazine, scan and asses, slowly reholster. Go and score/mark the target. If you were over the 25 second mark, that is fine, no need to drop points as this is a diagnostic progression as much as a standard, put two tick marks on the ten holes you just shot.
For the last ten round magazine, go back to 25 yards, get your natural point of aim and set your counter to 10 seconds or let your shot timer go off. Ten seconds standing freestyle, at high (or low, if that's your thing) ready. After the ten rounds are fired, if you do not have another magazine, make sure you deploy another weapon system, scan, assess, reload if needed and make sure you slowly reholster.
Go back up to the target and put three tick marks on the last ten rounds in the target.
Above target is, again, a 200 drill target, I shot in 2015. Now you connect the outline of the 1 tick marks, then the outline of the 2 tick marks, then the outline of the 3 tick marks. The middle of these shapes will show your point of impact. Ideally they should all be within the ten ring and you should be getting 95+ with each 100 drill.
Reasoning:
I would caution you not to do this diagnostic/drill progression more than once. If you want to do three not timed slow fire 100 drills, great do that, but try not to do more. We have all suffered an accuracy fatigue at one point or another, especially after a long day of shooting, the progression I explained above will probably put you at your limit. If you want to keep shooting, you should get up close 5-7 yards and run other types of speed drills, but I would recommend not doing another 100 drill at that time.
This is an especially good diagnostic tool self-assessment tool. If you show up to the range and run a 100 or 200 drill, shooting vastly under your last three 100 or 200 drills, you should pack up what you are doing and go home, because you need to make up the accuracy with dry fire. You will not fix a perceived issue at the range and you should get some dry fire in before you go back to shoot another 100 or 200 drill. If you think that it is your gun's fault, then I would either recommend having a buddy shoot the same drill with your gun or have another gun which is extremely accurate and vetted (like one with an RMR/T1 or with very accurate iron sights), run the same drill after a few minutes of "cooling off" if you shoot the same/near same result then it's you, if you shoot noticeably more accurate, then it may be the gun, but correlation does not imply causation, it is still up to to figure what is going on.
Advanced:
If you are extremely accurate in the three round progression I detailed above, then you should either reduce the target size, or the time constraint. I would still recommend shooting ten rounds without a time limit first to get a baseline, you will likely not do better than that baseline in the other two iterations of the progressions but if you do then something is going on which you should probably figure out. I would recommend reducing the 25 second time to 15 and the 10 to 7 or 8 seconds, as there is no reason to turn money into noise and you should get something out of shooting live ammo.
Considerations:
You should use quality ammo, whatever ammo which you have determined to accurate in your particular pistol. Do not shoot this with steel cased, bottom dollar, ammo. Shoot the entire progression with the same ammo do not mix it up, 115gr, then 147gr, etc, that will skew your results and hinder your development.
Keep track of your targets, you can take a photo with your cellphone and save them for future review, you can write down your scores in a log, you can hold a standard of 90+ or 95+ and count how many times you made the standard versus how many times you did not, etc. You can figure out what is the best process for you to keep yourself accountable.
Dry Fire:
This is the easy part of this entire concept and the follow through. Everyday you should dry fire thirty rounds, two hand standing free style at a target which is smaller than your front sight. Bill Rapier talks about this concept for dry fire and I like it. I use a pen at about ten yards away. It should be thinner than your front sight at that distance, pick a point on it (if it is a sharpie you can choose the section which divides the cap from the body/color difference for reference). Thirty perfect dry fires. Using the same principles as stated above, natural point of aim, breathing, not holding your arms out for longer than four seconds, resetting if necessary but make you are focusing on the front sight and completing a perfect trigger press. If you do the dry fire time you will see your accuracy standard go up.