Learn to practice tracking your sights at speed. What I did for this was:
-30-50 rounds a session of the following. Put the target up at 3-5 yards. Start aimed at the target and start with slow trigger presses, focusing on how your sights are tracking. When your sights look like a sewing machine (very little upward movement) start speeding up at the rate you can continue to keep your sights like that. Push yourself so that the last 4-5 shots are at the top of your speed.
The drill looks like this
Acceleration
The point is you're learning to track your sights and diagnose your recoil control as well. Rob Leatham has a video where he does a very similar thing as well, I'll try to edit my post with it later.
Cadence based methods are OK if you just want to learn to push your trigger speed past where you are comfortable, but I find that people tend to perform them improperly by not gripping the gun properly at the slower cadences. This means when they try to speed up, the gun is jumping all over.
Here is a cadence based method of shooting using a metronome. I got the metronome idea from Travis Haleys D5 handgun class
Cadence based - for what it's worth he said I had the best shooting platform in the entire class, which was held at Sig academy and consisted of quite a few Sig instructors as students as well. The key on this drill is to make sure you are gripping the gun and achieving that "sewing machine" effect on the slower runs as well as the faster runs.
These are both deliberate practice methods to improving your speed, and are designed to isolate your recoil control, sight tracking, and speed without a timer. They should be used in conjunction with a timer in later drills to test what you've done, keeping in mind that the more you add to the drill in terms of stacking skills might take away from being able to diagnose your recoil control and speed issues.
I personally like the "acceleration" drill because it forces you to pay attention to your sights and refine your grip as you see errors in that sight tracking. This will help you no matter what the target is. For reference, here are two Bill drills I did on Saturday, one video is around 10 yards, and 1 is at 25 yards, both on uspsa A/C steel from concealment (trex raptor AIWB holster, middle target in video)
25 yards 3.06s -
25 yd Bill drill 3.06 concealment
10 yards, 2 runs 1.94 each (1.19 draw, 0.13-0.15 splits for the second, not sure of breakdown for first, but same overall time). Didn't realize my camera didn't get the time bc of the backlight -
10 yd Bill drill concealment
I did a lot of the acceleration drill and some of the cadence drill for about a year every session (3x a month on average i went to the range) before I was able to get to this level of proficiency, and I still continue to do this drill, except now im working to develop one handed control as well. If you guys have any questions about anything I mentioned here, feel free to let me know.
Also, in dryfire make sure you are gripping the gun as tightly as you would in live fire. If you sacrifice grip in dryfire for trigger dexterity, in live fire you will feel like the gun is jumping around a lot
Hope this is helpful, as it's helped me a lot