I can't say I've found the secret myself but I found a couple resources that might be helpful to you.
http://web.extension.illinois.edu/gardendesign/placement_dominant.cfm
This guide from the university of Illinois has you pick a few dominant plants for each season and arrange their placement so that the garden remains balanced as time goes by.
http://www.urbandomesticdiva.com/2011/03/gardening-garden-plan-week-week-2-three.html
Spring Hill used to have a garden plan that was for 3 seasons. It's no longer available but this blog has information about it that you can use as inspiration.
http://www.gardengatenotes.com/2014/02/11/fitting-in-3-season-color/
Garden gate also has a simple guide to planting for 3 seasons.
Hopefully those might help
Q