Graft your knitting with a garter stitch edge as used in my Ambiguous cowl.
Demonstrated in two-handed knitting for catching yarn held in right hand (background color) and left hand (main/pattern color).
The position of the yarns in the hand determines which color is dominant in the design. Positioning options are demonstrated for two-handed, one-handed Continental and one-handed Western-style (throwing). Very important for Fair-Isle knitting.