I flag the easiest way when talking about planting. I choose the biggest and most flourishing flowers from a garden store and stuck them into the pots with some soil. I have no green thumb really, but still my entrance looks good enough. Sure I water the flowers frequently but that's all I do, and at least so far my tactic has worked just fine. The easier the better! To my neighbors I claim with bright eyes that the pretty flowers have something to do with my roots in countryside. ;-) ...just kidding!
This is not the door I use frequently. Just in case you wonder. ;-)