Choose your color palette.
1-2 neutrals and 3 complementary colors. The goal is coordination, not matching. I personally like to start with a feature piece, something with a print or maybe just a few colors and then pull the complementary colors from this. You only want 1 maybe 2 of these star pieces. As they can draw attention away from your face.
For fall I LOVE JEWAL TONES! At least having one really works well with the green oranges and reds of the fall leaves.
Once you have that chosen, your next selection should be your neutrals. Having 2 is good because we don't want the entire family wearing khakis, its good to break it up with either black or denim or maybe grey pants. When choosing this also consider placement, I am less likely to place people wearing the same color right next t each other because then you turn into a blob of color instead of individuals.
Simple tops are less distracting and really compliment the individual.
Once these are covered add layers accessories, these can really make for a finished look! Some examples:
Cardigan seaters
Blazers
Sport coats
Vest
Scarves
Ties/bow ties
Suspenders
Hair bows
tights/leggings
Belts
Head bands
Another way to add dimension and variety is to use a combination of materials and textures. For fall I love anything cozy, cable knit seaters, corduroy, velvet, leather boots.