[RichardTaylor]

Re reflectors.
I have only used them indoors for still life.

For outdoors this may help.

Using Gold Reflectors for Effect | LIGHTING ESSENTIALS For Photographers

and

BetterPhoto Instructor Insights: Using a gold reflector for faces

Re fill in flash.

See this tutorial from Canon.
Canon Digital Learning Center - Fill-Flash use with EOS cameras and speedlites