I've been natural since 2009 and it has taken me awhile to figure out how to get a really defined wash-n-go.  I tried many different products, but when it comes to doing a wash-n-go, my hair only loves Cantu's Leave-In Conditioning Cream, Eco Styler Olive Oil Gel, and unrefined organic coconut oil.  I start my wash-n-go on freshly shampooed hair.  Before adding product, I make sure to fully saturate my hair with water and detangle.  Starting from the back of my head, I apply a decent amount of hair cream to a small section and use my fingers to comb the product through.  Afterwards, I add gel and then seal it with coconut oil.  I do this in small sections until my hair is completely saturated with product.  Do not be afraid to go heavy handed with the cream and gel.  If my hair seems like it's still a little dry, I add some water to activate my curls more.  After all of the product is added, my hair feels weighed down and stretched out.  My curls are elongated at this point.  I scrunch my hair to remove some of the water and then I dry my hair on low heat and low speed, using a diffuser.  I always turn my head to the side or put it down so that my hair can fall into the prongs of the diffuser.  Using a diffuser to dry your curls is very important to achieving a defined wash-n-go.  I noticed that my hair doesn't have frizz whenever I dry my hair with a diffuser instead of letting it air dry.  The diffuser is important because it allows air to be dispersed over a larger area, instead of the air being concentrated on one section.  This way, the curl pattern is not interrupted, which in return reduces frizz.  Whenever I do my wash-n-go this way, I get the best results and it lasts five days.  Try this method out and let me know how it works for you.