I really like packing to go away - feeling that's all I've got and it's so easy!
So I'd choose a three tone palette - I often have black, turquoise and teal, or black, grey and white, or autumn tones rust, olive, brown, which is hard to do in summer! And bag and shades to tone.
Starting with your own colours can work too - taking your hair, eye and skin tone as your basic pallette. Mine's mid brown, teal, cream.
I like a kind of ancient Greek/Roman look - I love the women's costumes on Plebs. Usually an ankle length dress, flat sandals and important earrings/necklace.
And scarves. Very big and very thin, as Trinny says, because you can wrap and tie them into tops, jackets, wraps, skirts - brilliant.
Then sandals in gold/bronze, silver/pewter, brown/tan to go with the chosen pallette.