Activities that evoke emotions of wonder, beauty and joy bring about the highest vibrations.

The better you are feeling the more you are allowing your manifestations to occur.

The older I'm getting, the more I see the value in how you do it.

I would say a 70% (how) / 30% (what) mix for me.

Also, your state while you are doing something a certain way also helps bring a higher vibration to the situation.

the vibrational level of the sender along with the motivational cause of the act in question do contribute

I don't think it's necessarily the activity itself that determines the vibration but rather how you feel while doing it. When you're doing something that you really enjoy or that gives you a sense of accomplishment or that feeling that you're being helpful, then naturally you're going to feel good and your vibration will be a reflection of this.

The how is usually determined by the meaningfulness of the activity - the more it means, the better effort you put forth and the better you feel, and the higher the vibration.