African-style pattern

I am replicating this graphic on 20-count black Aida in a repeating pattern, creating a border. I "sketched" the pattern out in a single line of backstitch, to get my spacing right. I know I will not get the same effect with thread as with paint, but what stitch/technique would you folks use to create the chunky-funky, kinetic look? Second image is my work in progress, have not started the inside bars. Thanks in advance!