He checks that he has 2.5 degs... when exactly should this magic number occur during the flare? 2 to 2.5 degs is the normal pitch when flying the glideslope. So if having 2.5 degs at touchdown it means no flare at all.
A better advice is to start practicing not looking at the instruments at all when below 300 feet, except of course for airspeed.
Fly a steady approach to 300 feet using the window, G/S or F/D, a combination or what ever you prefer. At 300 feet shift your focus to your aimpoint and keep it steady on the windscreen and crosscheck/adjust your speed as necessary. Below 200 feet disregard glide slope (and PAPI to some extend, if you have 4 reds you did something wrong anyway) as the G/S, PAPI and aimpoint are not necessarily co-located.
Steady aimpoint and steady speed is all you need.
This avoid the "surprise" when flying the instruments down to 100 feet and the suddenly having to adjust to the outside view (of course you should be able to fly the instruments down there as well, but nobody expects you to make a greaser after a hand flown raw data CAT2 approach).
Now that you are adjusted to looking out you will find that it's much easier to judge the flare precisely. Remember, as you cut the throttle to give a slight nose up to compensate, this is a movement of a magnitude that can be compensated with the wrist. For the last feets, fly it on to the runway. Let it come down. Much of the firmer landing comes from the instinct to keep it off. It never works. The 737 needs to be flow (gently) down, not held off.
Lastly eliminate any drift, be it from cross wind or from poor alignment, with sideslip. If you land with a drift you will get the familiar rattle of everything, no matter if your rate of descend is 50 feet upon touch down.
To sum up:
1) Look out
2) Compensate for cutting throttle
3) Eliminate drift
4) Fly it (gently) down to the runway