Best way to fair

[SVJOCO]

I’m new to fairing. I’ve sanded this area with 40grit on a longboard, but I’m left with areas (shiny; zoom in) that would probably not hand sand well (so I can add more fairing). Should I knock the whole area down with an orbital and then fair it all about instead? How is this normally handled?

[Jammer]

Use 120 grit on a sponge to roughen up low areas where you want adhesion.