Merit is just good karma.
However many times 'be here now' has been said, and by however many people, I find it easy to drift away from.
Even better than "be here now" is to be with your meditation object at all times. Nothing will progress you faster. Half your attention on life, half on your meditation object, whatever it may be... breathe, body sensations, ect (I don't know how you'd do it with noting). Eventually it will take off on its own and will happen effortlessly.
"So, umm, how do you share merit? What do you say"
Say who you are thanking and then be silent and give it a little time, about 10 seconds. Then do the same thing with another person. The more you can feel the emotion of gratitude the stronger it will be, but if you don't feel much that is fine as well.
By saying these things you automatically start the energetic process in your body of giving merit. You may even have certain tensions in your body released by because you have corrected an imbalance. Don't worry about the process, the merit will flow naturally where it needs to go the most.
So once again. Thank your dhamma teacher/lineage, thank dhamma in general, thank your parents, and anyone who has helped you
In terms of my own practice, perhaps it's time to start practicing metta seriously - it always strikes me as a powerful practice but I never think to do it.
Stick with your insight practice with a couple minutes of metta after each session. Insight is much stronger than metta.
Would you care to talk in any more detail about your comments on sharing merit?
No people exist. There is no one individual. It is just a giant energetic ecosystem with constant giving and receiving between beings. Merit is energetic currency. You need to pay back the people who have helped you, it is very beneficial for you.
What do you mean by bandwidth?
We have a rate at which we progress in Dhamma. This rate will reduce if you withdraw too much without giving back thanks.