I work with Archangel Raphael most when I need healing, when I need love, support + nourishment, when I have a toothache, when I don't understand what's happening in my body, when I'm scared about my health for a moment (which I think can happen to all of us).
The easiest way to work with him would be to visualize bright green / emerald light bathing the person/situation/body part, in question, and doing this several times throughout the day. The stronger you can hold this visualization, and really believe that there is green light moving through you, the better. So get those those to a positive, supporting role: "This really is clearing the issue." "Archangel Raphael is indeed helping me."
Lots of love, and enjoy meditating with Raphael!